feat: config files, settings screen, hardware check

- Add config.py with multi-source config (YAML, .env, env vars)
- Add .env.example and config.yaml.example
- Add settings API endpoints (GET/POST /api/v1/settings)
- Add status endpoint (GET /api/v1/status) with hardware subsystem check
- Add settings screen to web client (protected by API token)
- Add localization strings for settings UI
- Add tests for config module and new endpoints
- Update README with config documentation

README.md

@@ -66,7 +66,10 @@ flowchart TD
 - **Media Playback Tracking** — Song title, artist, playback percentage, and cover art via Windows GSMTC
 - **Audio Mixer Control** — Real-time volume and mute from Windows default output or Voicemeeter per-strip gains, mutes, and track states
 - **Hardware Telemetry** — CPU/GPU core temps, VRAM usage from HWiNFO64
+- **Hardware Fallbacks** — Startup check reports which subsystems are available/unavailable
 - **Custom Notifications** — External scripts can push progress bars or rich text alerts via `POST /api/v1/notify`
+- **Settings Screen** — Change PIN and API token via the web client (protected by API token)
+- **Configuration Files** — Use `config.yaml`, `.env`, or environment variables
 - **E-Ink Optimized UI** — High-contrast styling, discrete zone gestures, minimal refresh
 - **System Tray .exe** — Runs unobtrusively in the Windows notification bar with a quit option
 
@@ -84,12 +87,14 @@ e-ink-dash/
 │   └── paperdash_architecture_document.txt
 ├── server/                # Python FastAPI server
 │   ├── main.py            # Application entry point
+│   ├── config.py          # Configuration management (YAML/.env/env vars)
 │   ├── audio_mixer.py     # Audio mixer abstraction (Windows + Voicemeeter)
 │   ├── media.py           # Media playback tracking (GSMTC)
 │   ├── notifications.py   # Notification system (progress + alerts)
 │   ├── telemetry.py       # Hardware telemetry (HWiNFO)
 │   ├── tray_wrapper.py    # System tray .exe wrapper
 │   ├── build_exe.py       # PyInstaller build script
+│   ├── .env.example       # Example environment file
 │   ├── requirements.txt
 │   └── tests/             # Test suite
 ├── client/                # E-Ink web client
@@ -113,10 +118,27 @@ pip install -r requirements.txt
 python -m uvicorn main:app --host 0.0.0.0 --port 8921
 ```
 
-Set environment variables:
+Configure via one of:
 
-- `DASHBOARD_PIN` — 4-digit PIN for the E-Ink client
-- `API_TOKEN` — Bearer token for external scripts
+1. **Environment variables:**
+   - `DASHBOARD_PIN` — 4-digit PIN for the E-Ink client
+   - `API_TOKEN` — Bearer token for external scripts
+
+2. **`.env` file** (in project root or exe directory):
+
+   ```
+   DASHBOARD_PIN=1234
+   API_TOKEN=your-token-here
+   ```
+
+3. **`config.yaml`** (in project root or exe directory):
+
+   ```yaml
+   dashboard_pin: "1234"
+   api_token: "your-token-here"
+   ```
+
+See `.env.example` and `config.yaml.example` for reference.
 
 ### Build .exe
 
@@ -144,6 +166,40 @@ adb install app/build/outputs/apk/debug/app-debug.apk
 
 The WebView loads `file:///android_asset/index.html` and connects to the server via WebSocket at `ws://<pc-ip>:8921/ws`.
 
+#### Localization
+
+The app supports multiple languages via Android string resources. The web client loads strings from Android via a JavaScript interface.
+
+**Adding a new language:**
+
+1. Create a new values folder: `android/app/src/main/res/values-{lang}/`
+   - Example: `values-es/` for Spanish, `values-fr/` for French
+2. Copy `values/strings.xml` to the new folder
+3. Translate the string values
+
+**Example `values-es/strings.xml`:**
+
+```xml
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">PaperDash</string>
+    <string name="login_title">PaperDash</string>
+    <string name="login_subtitle">Ingrese PIN para conectar</string>
+    <string name="login_placeholder">****</string>
+    <string name="login_button">Conectar</string>
+    <string name="login_error_enter_pin">Ingrese un PIN</string>
+    <string name="login_error_disconnected">Desconectado. Reingrese PIN.</string>
+    <string name="connecting">Conectando…</string>
+    <string name="no_playback">Sin reproducción</string>
+    <string name="mute">SILENCIAR</string>
+    <string name="muted">SILENCIADO</string>
+    <string name="no_notifications">Sin notificaciones</string>
+    <string name="eta_prefix">ETA:</string>
+</resources>
+```
+
+The app automatically uses the device's language. No code changes needed.
+
 ### Design Decisions
 
 See `.pi/docs/design/` for detailed design decision records covering architecture, audio mixer, notifications, and the .exe build.

android/app/src/main/assets/app.js

@@ -4,18 +4,92 @@
  * Connects to the PaperDash server via WebSocket.
  * Uses vanilla JS with direct DOM manipulation (element.textContent)
  * to minimize E-Ink refresh flashing.
+ *
+ * Strings are loaded from Android resources via the JavaScript interface.
  */
 
 (() => {
 	const SERVER_WS = `ws://${window.location.host}/ws`;
+	const SERVER_API = `http://${window.location.host}`;
 	const PIN_INPUT = document.getElementById("pin-input");
 	const CONNECT_BTN = document.getElementById("connect-btn");
 	const LOGIN_ERROR = document.getElementById("login-error");
 	const LOGIN_SCREEN = document.getElementById("login-screen");
 	const DASHBOARD_SCREEN = document.getElementById("dashboard-screen");
+	const SETTINGS_SCREEN = document.getElementById("settings-screen");
+	const SETTINGS_TOKEN_INPUT = document.getElementById("settings-token-input");
+	const SETTINGS_ACCESS_BTN = document.getElementById("settings-access-btn");
+	const SETTINGS_ERROR = document.getElementById("settings-error");
+	const SETTINGS_CONTENT = document.getElementById("settings-content");
+	const SETTINGS_PIN = document.getElementById("settings-pin");
+	const SETTINGS_TOKEN = document.getElementById("settings-token");
+	const SETTINGS_SAVE_BTN = document.getElementById("settings-save-btn");
+	const SETTINGS_BACK_BTN = document.getElementById("settings-back-btn");
+	const SETTINGS_STATUS = document.getElementById("settings-status");
+	const BTN_SETTINGS = document.getElementById("btn-settings");
 
 	let ws = null;
 	let reconnectTimer = null;
+	let currentApiToken = "";
+	const strings = {};
+
+	// -----------------------------------------------------------------------
+	// Localization
+	// -----------------------------------------------------------------------
+
+	function loadStrings() {
+		if (window.Android && window.Android.getString) {
+			const keys = [
+				"login_error_enter_pin",
+				"connecting",
+				"login_error_disconnected",
+				"no_playback",
+				"mute",
+				"muted",
+				"no_notifications",
+				"eta_prefix",
+				"settings_title",
+				"settings_subtitle",
+				"access",
+				"dashboard_pin_label",
+				"api_token_label",
+				"save",
+				"back",
+				"settings_error_invalid_token",
+				"settings_saved",
+				"settings_error_save_failed",
+			];
+			keys.forEach((key) => {
+				strings[key] = window.Android.getString(key);
+			});
+		}
+		applyStrings();
+	}
+
+	function applyStrings() {
+		// Apply data-i18n attributes
+		document.querySelectorAll("[data-i18n]").forEach((el) => {
+			const key = el.getAttribute("data-i18n");
+			if (strings[key]) {
+				el.textContent = strings[key];
+			}
+		});
+
+		// Apply data-i18n-placeholder attributes
+		document.querySelectorAll("[data-i18n-placeholder]").forEach((el) => {
+			const key = el.getAttribute("data-i18n-placeholder");
+			if (strings[key]) {
+				el.placeholder = strings[key];
+			}
+		});
+	}
+
+	// Load strings when DOM is ready
+	if (document.readyState === "loading") {
+		document.addEventListener("DOMContentLoaded", loadStrings);
+	} else {
+		loadStrings();
+	}
 
 	// -----------------------------------------------------------------------
 	// PIN Login
@@ -24,13 +98,13 @@
 	function connect() {
 		const pin = PIN_INPUT.value.trim();
 		if (!pin) {
-			LOGIN_ERROR.textContent = "Enter a PIN";
+			LOGIN_ERROR.textContent = strings.login_error_enter_pin || "Enter a PIN";
 			return;
 		}
 
 		LOGIN_ERROR.textContent = "";
 		CONNECT_BTN.disabled = true;
-		CONNECT_BTN.textContent = "Connecting...";
+		CONNECT_BTN.textContent = strings.connecting || "Connecting...";
 
 		ws = new WebSocket(`${SERVER_WS}?pin=${encodeURIComponent(pin)}`);
 
@@ -38,7 +112,7 @@
 			LOGIN_SCREEN.classList.remove("active");
 			DASHBOARD_SCREEN.classList.add("active");
 			CONNECT_BTN.disabled = false;
-			CONNECT_BTN.textContent = "Connect";
+			CONNECT_BTN.textContent = strings.login_button || "Connect";
 		};
 
 		ws.onmessage = (event) => {
@@ -53,9 +127,10 @@
 		ws.onclose = () => {
 			DASHBOARD_SCREEN.classList.remove("active");
 			LOGIN_SCREEN.classList.add("active");
-			LOGIN_ERROR.textContent = "Disconnected. Re-enter PIN.";
+			LOGIN_ERROR.textContent =
+				strings.login_error_disconnected || "Disconnected. Re-enter PIN.";
 			CONNECT_BTN.disabled = false;
-			CONNECT_BTN.textContent = "Connect";
+			CONNECT_BTN.textContent = strings.login_button || "Connect";
 
 			// Auto-reconnect after 5 seconds
 			clearTimeout(reconnectTimer);
@@ -91,7 +166,7 @@
 	// -----------------------------------------------------------------------
 
 	function updateMedia(media) {
-		setText("track-title", media.title || "No playback");
+		setText("track-title", media.title || strings.no_playback || "No playback");
 		setText("track-artist", media.artist || "");
 		setText("track-album", media.album || "");
 
@@ -127,10 +202,10 @@
 		const muteBtn = document.getElementById("btn-mute");
 		if (audio.master_muted) {
 			muteBtn.classList.add("muted");
-			muteBtn.textContent = "MUTED";
+			muteBtn.textContent = strings.muted || "MUTED";
 		} else {
 			muteBtn.classList.remove("muted");
-			muteBtn.textContent = "MUTE";
+			muteBtn.textContent = strings.mute || "MUTE";
 		}
 
 		// Channels — use DOM API
@@ -211,7 +286,7 @@
 		if (!notifications || notifications.length === 0) {
 			const p = document.createElement("p");
 			p.style.color = "#888";
-			p.textContent = "No notifications";
+			p.textContent = strings.no_notifications || "No notifications";
 			container.appendChild(p);
 			return;
 		}
@@ -244,7 +319,7 @@
 				if (n.eta) {
 					const etaDiv = document.createElement("div");
 					etaDiv.className = "notification-eta";
-					etaDiv.textContent = "ETA: " + n.eta;
+					etaDiv.textContent = (strings.eta_prefix || "ETA:") + " " + n.eta;
 					div.appendChild(etaDiv);
 				}
 
@@ -365,4 +440,96 @@
 		const s = Math.floor(seconds % 60);
 		return m + ":" + (s < 10 ? "0" : "") + s;
 	}
+
+	// -----------------------------------------------------------------------
+	// Settings
+	// -----------------------------------------------------------------------
+
+	function showSettings() {
+		DASHBOARD_SCREEN.classList.remove("active");
+		SETTINGS_SCREEN.classList.add("active");
+		SETTINGS_ERROR.textContent = "";
+		SETTINGS_STATUS.textContent = "";
+		SETTINGS_TOKEN_INPUT.value = "";
+		SETTINGS_CONTENT.style.display = "none";
+	}
+
+	function hideSettings() {
+		SETTINGS_SCREEN.classList.remove("active");
+		DASHBOARD_SCREEN.classList.add("active");
+	}
+
+	async function accessSettings() {
+		const token = SETTINGS_TOKEN_INPUT.value.trim();
+		if (!token) {
+			SETTINGS_ERROR.textContent =
+				strings.settings_error_invalid_token || "Invalid token";
+			return;
+		}
+
+		try {
+			const response = await fetch(`${SERVER_API}/api/v1/settings`, {
+				headers: {
+					Authorization: `Bearer ${token}`,
+				},
+			});
+
+			if (!response.ok) {
+				SETTINGS_ERROR.textContent =
+					strings.settings_error_invalid_token || "Invalid token";
+				return;
+			}
+
+			const data = await response.json();
+			currentApiToken = token;
+			SETTINGS_ERROR.textContent = "";
+			SETTINGS_PIN.value = data.dashboard_pin || "";
+			SETTINGS_TOKEN.value = data.api_token || "";
+			SETTINGS_CONTENT.style.display = "block";
+		} catch (err) {
+			SETTINGS_ERROR.textContent =
+				strings.settings_error_invalid_token || "Invalid token";
+		}
+	}
+
+	async function saveSettings() {
+		const pin = SETTINGS_PIN.value.trim();
+		const token = SETTINGS_TOKEN.value.trim();
+
+		try {
+			const response = await fetch(`${SERVER_API}/api/v1/settings`, {
+				method: "POST",
+				headers: {
+					"Content-Type": "application/json",
+					Authorization: `Bearer ${currentApiToken}`,
+				},
+				body: JSON.stringify({
+					dashboard_pin: pin,
+					api_token: token,
+				}),
+			});
+
+			if (!response.ok) {
+				SETTINGS_STATUS.textContent =
+					strings.settings_error_save_failed || "Failed to save settings";
+				return;
+			}
+
+			SETTINGS_STATUS.textContent =
+				strings.settings_saved || "Settings saved";
+			currentApiToken = token;
+		} catch (err) {
+			SETTINGS_STATUS.textContent =
+				strings.settings_error_save_failed || "Failed to save settings";
+		}
+	}
+
+	// Settings event listeners
+	BTN_SETTINGS.addEventListener("click", showSettings);
+	SETTINGS_ACCESS_BTN.addEventListener("click", accessSettings);
+	SETTINGS_SAVE_BTN.addEventListener("click", saveSettings);
+	SETTINGS_BACK_BTN.addEventListener("click", hideSettings);
+	SETTINGS_TOKEN_INPUT.addEventListener("keydown", (e) => {
+		if (e.key === "Enter") accessSettings();
+	});
 })();

android/app/src/main/assets/index.html

@@ -8,34 +8,40 @@
     />
     <meta name="apple-mobile-web-app-capable" content="yes" />
     <meta name="mobile-web-app-capable" content="yes" />
-    <title>PaperDash</title>
+    <title data-i18n="app_name">PaperDash</title>
     <link rel="stylesheet" href="style.css" />
   </head>
   <body>
     <div id="app">
       <!-- PIN Login Screen -->
       <div id="login-screen" class="screen active">
-        <h1>PaperDash</h1>
-        <p>Enter PIN to connect</p>
+        <h1 data-i18n="login_title">PaperDash</h1>
+        <p data-i18n="login_subtitle">Enter PIN to connect</p>
         <input
           type="password"
           id="pin-input"
           maxlength="4"
+          data-i18n-placeholder="login_placeholder"
           placeholder="****"
           autocomplete="off"
         />
-        <button id="connect-btn">Connect</button>
+        <button id="connect-btn" data-i18n="login_button">Connect</button>
         <p id="login-error" class="error"></p>
       </div>
 
       <!-- Main Dashboard -->
       <div id="dashboard-screen" class="screen">
+        <!-- Settings Button -->
+        <button id="btn-settings" class="settings-btn">⚙</button>
+
         <!-- Media Section -->
         <section id="media-section" class="panel">
-          <h2>Now Playing</h2>
+          <h2 data-i18n="now_playing">Now Playing</h2>
           <div id="artwork-container"></div>
           <div id="track-info">
-            <div id="track-title" class="track-title">No playback</div>
+            <div id="track-title" class="track-title" data-i18n="no_playback">
+              No playback
+            </div>
             <div id="track-artist" class="track-artist"></div>
             <div id="track-album" class="track-album"></div>
           </div>
@@ -57,22 +63,24 @@
 
         <!-- Audio Mixer Section -->
         <section id="audio-section" class="panel">
-          <h2>Audio Mixer</h2>
+          <h2 data-i18n="audio_mixer">Audio Mixer</h2>
           <div id="master-volume">
-            <span id="master-label">Master</span>
+            <span id="master-label" data-i18n="master_label">Master</span>
             <div class="volume-controls">
               <button id="btn-vol-down" class="volume-btn">-</button>
               <span id="master-volume-value">50%</span>
               <button id="btn-vol-up" class="volume-btn">+</button>
             </div>
-            <button id="btn-mute" class="mute-btn">MUTE</button>
+            <button id="btn-mute" class="mute-btn" data-i18n="mute">
+              MUTE
+            </button>
           </div>
           <div id="channels-container"></div>
         </section>
 
         <!-- Telemetry Section -->
         <section id="telemetry-section" class="panel">
-          <h2>System</h2>
+          <h2 data-i18n="system">System</h2>
           <div id="telemetry-grid">
             <div class="telemetry-item">
               <span class="telemetry-label">CPU</span>
@@ -95,10 +103,49 @@
 
         <!-- Notifications Section -->
         <section id="notifications-section" class="panel">
-          <h2>Notifications</h2>
+          <h2 data-i18n="notifications">Notifications</h2>
           <div id="notifications-container"></div>
         </section>
       </div>
+
+      <!-- Settings Screen -->
+      <div id="settings-screen" class="screen">
+        <h1 data-i18n="settings_title">Settings</h1>
+        <p data-i18n="settings_subtitle">Enter API token to access settings</p>
+        <input
+          type="password"
+          id="settings-token-input"
+          placeholder="API Token"
+          autocomplete="off"
+        />
+        <button id="settings-access-btn" data-i18n="access">Access</button>
+        <p id="settings-error" class="error"></p>
+
+        <div id="settings-content" style="display: none;">
+          <section class="panel">
+            <h2 data-i18n="dashboard_pin_label">Dashboard PIN</h2>
+            <input
+              type="text"
+              id="settings-pin"
+              maxlength="4"
+              placeholder="****"
+            />
+          </section>
+
+          <section class="panel">
+            <h2 data-i18n="api_token_label">API Token</h2>
+            <input
+              type="password"
+              id="settings-token"
+              placeholder="API Token"
+            />
+          </section>
+
+          <button id="settings-save-btn" data-i18n="save">Save</button>
+          <button id="settings-back-btn" data-i18n="back">Back</button>
+          <p id="settings-status" class="status"></p>
+        </div>
+      </div>
     </div>
 
     <script src="app.js"></script>

android/app/src/main/assets/style.css

@@ -342,6 +342,107 @@ body {
 	overflow-x: hidden;
 }
 
+/* Settings button */
+.settings-btn {
+	position: absolute;
+	top: 10px;
+	right: 10px;
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	width: 40px;
+	height: 40px;
+	font-size: 1.2em;
+	cursor: pointer;
+	z-index: 100;
+	font-family: inherit;
+}
+
+/* Settings screen */
+#settings-screen {
+	justify-content: flex-start;
+	padding-top: 40px;
+}
+
+#settings-screen h1 {
+	font-size: 1.5em;
+	border-bottom: 2px solid var(--border);
+	padding-bottom: 8px;
+	margin-bottom: 12px;
+}
+
+#settings-screen p {
+	margin-bottom: 12px;
+	color: var(--dim);
+}
+
+#settings-token-input {
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	padding: 10px;
+	width: 100%;
+	margin-bottom: 10px;
+	font-family: inherit;
+	font-size: 1em;
+}
+
+#settings-access-btn,
+#settings-save-btn,
+#settings-back-btn {
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	padding: 10px 20px;
+	font-size: 1em;
+	cursor: pointer;
+	margin-right: 10px;
+	margin-bottom: 10px;
+	font-family: inherit;
+}
+
+#settings-content {
+	margin-top: 20px;
+}
+
+#settings-content .panel {
+	margin-bottom: 15px;
+}
+
+#settings-content h2 {
+	font-size: 0.9em;
+	margin-bottom: 8px;
+	color: var(--dim);
+}
+
+#settings-pin,
+#settings-token {
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	padding: 10px;
+	width: 100%;
+	font-family: inherit;
+	font-size: 1em;
+}
+
+#settings-status {
+	margin-top: 15px;
+	padding: 10px;
+	border: 2px solid var(--border);
+	background: var(--panel-bg);
+}
+
+.status {
+	color: var(--fg);
+}
+
+.error {
+	color: var(--dim);
+	font-size: 0.9em;
+	margin-top: 10px;
+}
+
 /* E-Ink specific: no transitions, sharp edges */
 * {
 	transition: none !important;

android/app/src/main/java/me/kareemhorstink/paperdash/MainActivity.kt

@@ -1,11 +1,14 @@
 package me.kareemhorstink.paperdash
 
 import android.annotation.SuppressLint
+import android.content.Context
 import android.os.Build
 import android.os.Bundle
+import android.util.Log
 import android.view.View
 import android.view.WindowInsets
 import android.view.WindowInsetsController
+import android.webkit.JavascriptInterface
 import android.webkit.WebSettings
 import android.webkit.WebView
 import android.webkit.WebViewClient
@@ -37,6 +40,9 @@ class MainActivity : AppCompatActivity() {
         webView.isVerticalScrollBarEnabled = false
         webView.overScrollMode = WebView.OVER_SCROLL_NEVER
 
+        // Add JavaScript interface for localized strings
+        webView.addJavascriptInterface(LocalizationInterface(this), "Android")
+
         // Hide system bars for full-screen E-Ink display
         hideSystemBars()
 
@@ -67,4 +73,26 @@ class MainActivity : AppCompatActivity() {
         super.onWindowFocusChanged(hasFocus)
         if (hasFocus) hideSystemBars()
     }
+
+    /**
+     * JavaScript interface that provides localized strings to the web client.
+     * Call from JavaScript: window.Android.getString("key")
+     */
+    inner class LocalizationInterface(context: Context) {
+        @JavascriptInterface
+        fun getString(key: String): String {
+            return try {
+                val resourceId = context.resources.getIdentifier(key, "string", context.packageName)
+                if (resourceId != 0) {
+                    context.resources.getString(resourceId)
+                } else {
+                    Log.w("PaperDash", "String resource not found: $key")
+                    ""
+                }
+            } catch (e: Exception) {
+                Log.e("PaperDash", "Error getting string: $key", e)
+                ""
+            }
+        }
+    }
 }

android/app/src/main/res/values/strings.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">PaperDash</string>
+    <string name="login_title">PaperDash</string>
+    <string name="login_subtitle">Enter PIN to connect</string>
+    <string name="login_placeholder">****</string>
+    <string name="login_button">Connect</string>
+    <string name="login_error_enter_pin">Enter a PIN</string>
+    <string name="login_error_disconnected">Disconnected. Re-enter PIN.</string>
+    <string name="connecting">Connecting…</string>
+    <string name="no_playback">No playback</string>
+    <string name="album_art_alt">Album art</string>
+    <string name="master_label">Master</string>
+    <string name="mute">MUTE</string>
+    <string name="muted">MUTED</string>
+    <string name="no_notifications">No notifications</string>
+    <string name="eta_prefix">ETA:</string>
+    <string name="settings_title">Settings</string>
+    <string name="settings_subtitle">Enter API token to access settings</string>
+    <string name="access">Access</string>
+    <string name="dashboard_pin_label">Dashboard PIN</string>
+    <string name="api_token_label">API Token</string>
+    <string name="save">Save</string>
+    <string name="back">Back</string>
+    <string name="settings_error_invalid_token">Invalid token</string>
+    <string name="settings_saved">Settings saved</string>
+    <string name="settings_error_save_failed">Failed to save settings</string>
+</resources>

client/app.js

@@ -4,18 +4,92 @@
  * Connects to the PaperDash server via WebSocket.
  * Uses vanilla JS with direct DOM manipulation (element.textContent)
  * to minimize E-Ink refresh flashing.
+ *
+ * Strings are loaded from Android resources via the JavaScript interface.
  */
 
 (() => {
 	const SERVER_WS = `ws://${window.location.host}/ws`;
+	const SERVER_API = `http://${window.location.host}`;
 	const PIN_INPUT = document.getElementById("pin-input");
 	const CONNECT_BTN = document.getElementById("connect-btn");
 	const LOGIN_ERROR = document.getElementById("login-error");
 	const LOGIN_SCREEN = document.getElementById("login-screen");
 	const DASHBOARD_SCREEN = document.getElementById("dashboard-screen");
+	const SETTINGS_SCREEN = document.getElementById("settings-screen");
+	const SETTINGS_TOKEN_INPUT = document.getElementById("settings-token-input");
+	const SETTINGS_ACCESS_BTN = document.getElementById("settings-access-btn");
+	const SETTINGS_ERROR = document.getElementById("settings-error");
+	const SETTINGS_CONTENT = document.getElementById("settings-content");
+	const SETTINGS_PIN = document.getElementById("settings-pin");
+	const SETTINGS_TOKEN = document.getElementById("settings-token");
+	const SETTINGS_SAVE_BTN = document.getElementById("settings-save-btn");
+	const SETTINGS_BACK_BTN = document.getElementById("settings-back-btn");
+	const SETTINGS_STATUS = document.getElementById("settings-status");
+	const BTN_SETTINGS = document.getElementById("btn-settings");
 
 	let ws = null;
 	let reconnectTimer = null;
+	let currentApiToken = "";
+	const strings = {};
+
+	// -----------------------------------------------------------------------
+	// Localization
+	// -----------------------------------------------------------------------
+
+	function loadStrings() {
+		if (window.Android && window.Android.getString) {
+			const keys = [
+				"login_error_enter_pin",
+				"connecting",
+				"login_error_disconnected",
+				"no_playback",
+				"mute",
+				"muted",
+				"no_notifications",
+				"eta_prefix",
+				"settings_title",
+				"settings_subtitle",
+				"access",
+				"dashboard_pin_label",
+				"api_token_label",
+				"save",
+				"back",
+				"settings_error_invalid_token",
+				"settings_saved",
+				"settings_error_save_failed",
+			];
+			keys.forEach((key) => {
+				strings[key] = window.Android.getString(key);
+			});
+		}
+		applyStrings();
+	}
+
+	function applyStrings() {
+		// Apply data-i18n attributes
+		document.querySelectorAll("[data-i18n]").forEach((el) => {
+			const key = el.getAttribute("data-i18n");
+			if (strings[key]) {
+				el.textContent = strings[key];
+			}
+		});
+
+		// Apply data-i18n-placeholder attributes
+		document.querySelectorAll("[data-i18n-placeholder]").forEach((el) => {
+			const key = el.getAttribute("data-i18n-placeholder");
+			if (strings[key]) {
+				el.placeholder = strings[key];
+			}
+		});
+	}
+
+	// Load strings when DOM is ready
+	if (document.readyState === "loading") {
+		document.addEventListener("DOMContentLoaded", loadStrings);
+	} else {
+		loadStrings();
+	}
 
 	// -----------------------------------------------------------------------
 	// PIN Login
@@ -24,13 +98,13 @@
 	function connect() {
 		const pin = PIN_INPUT.value.trim();
 		if (!pin) {
-			LOGIN_ERROR.textContent = "Enter a PIN";
+			LOGIN_ERROR.textContent = strings.login_error_enter_pin || "Enter a PIN";
 			return;
 		}
 
 		LOGIN_ERROR.textContent = "";
 		CONNECT_BTN.disabled = true;
-		CONNECT_BTN.textContent = "Connecting...";
+		CONNECT_BTN.textContent = strings.connecting || "Connecting...";
 
 		ws = new WebSocket(`${SERVER_WS}?pin=${encodeURIComponent(pin)}`);
 
@@ -38,7 +112,7 @@
 			LOGIN_SCREEN.classList.remove("active");
 			DASHBOARD_SCREEN.classList.add("active");
 			CONNECT_BTN.disabled = false;
-			CONNECT_BTN.textContent = "Connect";
+			CONNECT_BTN.textContent = strings.login_button || "Connect";
 		};
 
 		ws.onmessage = (event) => {
@@ -53,9 +127,10 @@
 		ws.onclose = () => {
 			DASHBOARD_SCREEN.classList.remove("active");
 			LOGIN_SCREEN.classList.add("active");
-			LOGIN_ERROR.textContent = "Disconnected. Re-enter PIN.";
+			LOGIN_ERROR.textContent =
+				strings.login_error_disconnected || "Disconnected. Re-enter PIN.";
 			CONNECT_BTN.disabled = false;
-			CONNECT_BTN.textContent = "Connect";
+			CONNECT_BTN.textContent = strings.login_button || "Connect";
 
 			// Auto-reconnect after 5 seconds
 			clearTimeout(reconnectTimer);
@@ -91,7 +166,7 @@
 	// -----------------------------------------------------------------------
 
 	function updateMedia(media) {
-		setText("track-title", media.title || "No playback");
+		setText("track-title", media.title || strings.no_playback || "No playback");
 		setText("track-artist", media.artist || "");
 		setText("track-album", media.album || "");
 
@@ -127,10 +202,10 @@
 		const muteBtn = document.getElementById("btn-mute");
 		if (audio.master_muted) {
 			muteBtn.classList.add("muted");
-			muteBtn.textContent = "MUTED";
+			muteBtn.textContent = strings.muted || "MUTED";
 		} else {
 			muteBtn.classList.remove("muted");
-			muteBtn.textContent = "MUTE";
+			muteBtn.textContent = strings.mute || "MUTE";
 		}
 
 		// Channels — use DOM API
@@ -211,7 +286,7 @@
 		if (!notifications || notifications.length === 0) {
 			const p = document.createElement("p");
 			p.style.color = "#888";
-			p.textContent = "No notifications";
+			p.textContent = strings.no_notifications || "No notifications";
 			container.appendChild(p);
 			return;
 		}
@@ -244,7 +319,7 @@
 				if (n.eta) {
 					const etaDiv = document.createElement("div");
 					etaDiv.className = "notification-eta";
-					etaDiv.textContent = "ETA: " + n.eta;
+					etaDiv.textContent = (strings.eta_prefix || "ETA:") + " " + n.eta;
 					div.appendChild(etaDiv);
 				}
 
@@ -365,4 +440,96 @@
 		const s = Math.floor(seconds % 60);
 		return m + ":" + (s < 10 ? "0" : "") + s;
 	}
+
+	// -----------------------------------------------------------------------
+	// Settings
+	// -----------------------------------------------------------------------
+
+	function showSettings() {
+		DASHBOARD_SCREEN.classList.remove("active");
+		SETTINGS_SCREEN.classList.add("active");
+		SETTINGS_ERROR.textContent = "";
+		SETTINGS_STATUS.textContent = "";
+		SETTINGS_TOKEN_INPUT.value = "";
+		SETTINGS_CONTENT.style.display = "none";
+	}
+
+	function hideSettings() {
+		SETTINGS_SCREEN.classList.remove("active");
+		DASHBOARD_SCREEN.classList.add("active");
+	}
+
+	async function accessSettings() {
+		const token = SETTINGS_TOKEN_INPUT.value.trim();
+		if (!token) {
+			SETTINGS_ERROR.textContent =
+				strings.settings_error_invalid_token || "Invalid token";
+			return;
+		}
+
+		try {
+			const response = await fetch(`${SERVER_API}/api/v1/settings`, {
+				headers: {
+					Authorization: `Bearer ${token}`,
+				},
+			});
+
+			if (!response.ok) {
+				SETTINGS_ERROR.textContent =
+					strings.settings_error_invalid_token || "Invalid token";
+				return;
+			}
+
+			const data = await response.json();
+			currentApiToken = token;
+			SETTINGS_ERROR.textContent = "";
+			SETTINGS_PIN.value = data.dashboard_pin || "";
+			SETTINGS_TOKEN.value = data.api_token || "";
+			SETTINGS_CONTENT.style.display = "block";
+		} catch (err) {
+			SETTINGS_ERROR.textContent =
+				strings.settings_error_invalid_token || "Invalid token";
+		}
+	}
+
+	async function saveSettings() {
+		const pin = SETTINGS_PIN.value.trim();
+		const token = SETTINGS_TOKEN.value.trim();
+
+		try {
+			const response = await fetch(`${SERVER_API}/api/v1/settings`, {
+				method: "POST",
+				headers: {
+					"Content-Type": "application/json",
+					Authorization: `Bearer ${currentApiToken}`,
+				},
+				body: JSON.stringify({
+					dashboard_pin: pin,
+					api_token: token,
+				}),
+			});
+
+			if (!response.ok) {
+				SETTINGS_STATUS.textContent =
+					strings.settings_error_save_failed || "Failed to save settings";
+				return;
+			}
+
+			SETTINGS_STATUS.textContent =
+				strings.settings_saved || "Settings saved";
+			currentApiToken = token;
+		} catch (err) {
+			SETTINGS_STATUS.textContent =
+				strings.settings_error_save_failed || "Failed to save settings";
+		}
+	}
+
+	// Settings event listeners
+	BTN_SETTINGS.addEventListener("click", showSettings);
+	SETTINGS_ACCESS_BTN.addEventListener("click", accessSettings);
+	SETTINGS_SAVE_BTN.addEventListener("click", saveSettings);
+	SETTINGS_BACK_BTN.addEventListener("click", hideSettings);
+	SETTINGS_TOKEN_INPUT.addEventListener("keydown", (e) => {
+		if (e.key === "Enter") accessSettings();
+	});
 })();

client/index.html

@@ -8,34 +8,40 @@
     />
     <meta name="apple-mobile-web-app-capable" content="yes" />
     <meta name="mobile-web-app-capable" content="yes" />
-    <title>PaperDash</title>
+    <title data-i18n="app_name">PaperDash</title>
     <link rel="stylesheet" href="style.css" />
   </head>
   <body>
     <div id="app">
       <!-- PIN Login Screen -->
       <div id="login-screen" class="screen active">
-        <h1>PaperDash</h1>
-        <p>Enter PIN to connect</p>
+        <h1 data-i18n="login_title">PaperDash</h1>
+        <p data-i18n="login_subtitle">Enter PIN to connect</p>
         <input
           type="password"
           id="pin-input"
           maxlength="4"
+          data-i18n-placeholder="login_placeholder"
           placeholder="****"
           autocomplete="off"
         />
-        <button id="connect-btn">Connect</button>
+        <button id="connect-btn" data-i18n="login_button">Connect</button>
         <p id="login-error" class="error"></p>
       </div>
 
       <!-- Main Dashboard -->
       <div id="dashboard-screen" class="screen">
+        <!-- Settings Button -->
+        <button id="btn-settings" class="settings-btn">⚙</button>
+
         <!-- Media Section -->
         <section id="media-section" class="panel">
-          <h2>Now Playing</h2>
+          <h2 data-i18n="now_playing">Now Playing</h2>
           <div id="artwork-container"></div>
           <div id="track-info">
-            <div id="track-title" class="track-title">No playback</div>
+            <div id="track-title" class="track-title" data-i18n="no_playback">
+              No playback
+            </div>
             <div id="track-artist" class="track-artist"></div>
             <div id="track-album" class="track-album"></div>
           </div>
@@ -57,22 +63,24 @@
 
         <!-- Audio Mixer Section -->
         <section id="audio-section" class="panel">
-          <h2>Audio Mixer</h2>
+          <h2 data-i18n="audio_mixer">Audio Mixer</h2>
           <div id="master-volume">
-            <span id="master-label">Master</span>
+            <span id="master-label" data-i18n="master_label">Master</span>
             <div class="volume-controls">
               <button id="btn-vol-down" class="volume-btn">-</button>
               <span id="master-volume-value">50%</span>
               <button id="btn-vol-up" class="volume-btn">+</button>
             </div>
-            <button id="btn-mute" class="mute-btn">MUTE</button>
+            <button id="btn-mute" class="mute-btn" data-i18n="mute">
+              MUTE
+            </button>
           </div>
           <div id="channels-container"></div>
         </section>
 
         <!-- Telemetry Section -->
         <section id="telemetry-section" class="panel">
-          <h2>System</h2>
+          <h2 data-i18n="system">System</h2>
           <div id="telemetry-grid">
             <div class="telemetry-item">
               <span class="telemetry-label">CPU</span>
@@ -95,10 +103,49 @@
 
         <!-- Notifications Section -->
         <section id="notifications-section" class="panel">
-          <h2>Notifications</h2>
+          <h2 data-i18n="notifications">Notifications</h2>
           <div id="notifications-container"></div>
         </section>
       </div>
+
+      <!-- Settings Screen -->
+      <div id="settings-screen" class="screen">
+        <h1 data-i18n="settings_title">Settings</h1>
+        <p data-i18n="settings_subtitle">Enter API token to access settings</p>
+        <input
+          type="password"
+          id="settings-token-input"
+          placeholder="API Token"
+          autocomplete="off"
+        />
+        <button id="settings-access-btn" data-i18n="access">Access</button>
+        <p id="settings-error" class="error"></p>
+
+        <div id="settings-content" style="display: none;">
+          <section class="panel">
+            <h2 data-i18n="dashboard_pin_label">Dashboard PIN</h2>
+            <input
+              type="text"
+              id="settings-pin"
+              maxlength="4"
+              placeholder="****"
+            />
+          </section>
+
+          <section class="panel">
+            <h2 data-i18n="api_token_label">API Token</h2>
+            <input
+              type="password"
+              id="settings-token"
+              placeholder="API Token"
+            />
+          </section>
+
+          <button id="settings-save-btn" data-i18n="save">Save</button>
+          <button id="settings-back-btn" data-i18n="back">Back</button>
+          <p id="settings-status" class="status"></p>
+        </div>
+      </div>
     </div>
 
     <script src="app.js"></script>

client/style.css

@@ -342,6 +342,107 @@ body {
 	overflow-x: hidden;
 }
 
+/* Settings button */
+.settings-btn {
+	position: absolute;
+	top: 10px;
+	right: 10px;
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	width: 40px;
+	height: 40px;
+	font-size: 1.2em;
+	cursor: pointer;
+	z-index: 100;
+	font-family: inherit;
+}
+
+/* Settings screen */
+#settings-screen {
+	justify-content: flex-start;
+	padding-top: 40px;
+}
+
+#settings-screen h1 {
+	font-size: 1.5em;
+	border-bottom: 2px solid var(--border);
+	padding-bottom: 8px;
+	margin-bottom: 12px;
+}
+
+#settings-screen p {
+	margin-bottom: 12px;
+	color: var(--dim);
+}
+
+#settings-token-input {
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	padding: 10px;
+	width: 100%;
+	margin-bottom: 10px;
+	font-family: inherit;
+	font-size: 1em;
+}
+
+#settings-access-btn,
+#settings-save-btn,
+#settings-back-btn {
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	padding: 10px 20px;
+	font-size: 1em;
+	cursor: pointer;
+	margin-right: 10px;
+	margin-bottom: 10px;
+	font-family: inherit;
+}
+
+#settings-content {
+	margin-top: 20px;
+}
+
+#settings-content .panel {
+	margin-bottom: 15px;
+}
+
+#settings-content h2 {
+	font-size: 0.9em;
+	margin-bottom: 8px;
+	color: var(--dim);
+}
+
+#settings-pin,
+#settings-token {
+	background: var(--bg);
+	color: var(--fg);
+	border: 2px solid var(--border);
+	padding: 10px;
+	width: 100%;
+	font-family: inherit;
+	font-size: 1em;
+}
+
+#settings-status {
+	margin-top: 15px;
+	padding: 10px;
+	border: 2px solid var(--border);
+	background: var(--panel-bg);
+}
+
+.status {
+	color: var(--fg);
+}
+
+.error {
+	color: var(--dim);
+	font-size: 0.9em;
+	margin-top: 10px;
+}
+
 /* E-Ink specific: no transitions, sharp edges */
 * {
 	transition: none !important;

config.yaml.example

@@ -0,0 +1,9 @@
+# PaperDash Configuration
+# Copy this file to config.yaml and fill in your values
+
+dashboard_pin: "1234"
+api_token: "your-secret-token-here"
+
+host: "0.0.0.0"
+port: 8921
+log_level: INFO

server/.env.example

@@ -0,0 +1,13 @@
+# PaperDash Configuration
+# Copy this file to .env and fill in your values
+
+# Dashboard PIN (4-digit code for the E-Ink client)
+DASHBOARD_PIN=1234
+
+# API Token (Bearer token for external scripts)
+API_TOKEN=your-secret-token-here
+
+# Server settings
+HOST=0.0.0.0
+PORT=8921
+LOG_LEVEL=INFO

server/config.py

@@ -0,0 +1,176 @@
+"""Configuration management for PaperDash.
+
+Loads config from:
+1. config.yaml (if exists)
+2. .env file (if exists)
+3. Environment variables (fallback)
+"""
+
+from __future__ import annotations
+
+import logging
+import os
+import sys
+from pathlib import Path
+from typing import Any
+
+logger = logging.getLogger("paperdash.config")
+
+# Try to import yaml, fall back to simple parser
+try:
+    import yaml
+    HAS_YAML = True
+except ImportError:
+    HAS_YAML = False
+
+
+class Config:
+    """PaperDash configuration."""
+
+    def __init__(self) -> None:
+        self.dashboard_pin: str = ""
+        self.api_token: str = ""
+        self.host: str = "0.0.0.0"
+        self.port: int = 8921
+        self.log_level: str = "INFO"
+
+    def load(self) -> None:
+        """Load configuration from all sources."""
+        # 1. Load config.yaml
+        config_file = self._find_config_file()
+        if config_file and config_file.exists():
+            self._load_yaml(config_file)
+
+        # 2. Load .env file
+        env_file = self._find_env_file()
+        if env_file and env_file.exists():
+            self._load_env(env_file)
+
+        # 3. Environment variables override everything
+        self._load_from_env()
+
+        # Validate
+        if not self.dashboard_pin:
+            logger.warning("DASHBOARD_PIN not set — WebSocket auth will be disabled")
+        if not self.api_token:
+            logger.warning("API_TOKEN not set — /api/v1/notify will reject all requests")
+
+    def _get_base_path(self) -> Path:
+        """Get base path (exe directory or cwd)."""
+        if getattr(sys, 'frozen', False):
+            return Path(sys.executable).parent
+        return Path.cwd()
+
+    def _find_config_file(self) -> Path | None:
+        """Find config.yaml relative to the executable or working directory."""
+        base = self._get_base_path()
+        for candidate in [base] + list(base.parents):
+            config_path = candidate / "config.yaml"
+            if config_path.exists():
+                return config_path
+        return None
+
+    def _find_env_file(self) -> Path | None:
+        """Find .env file relative to the executable or working directory."""
+        base = self._get_base_path()
+        for candidate in [base] + list(base.parents):
+            env_path = candidate / ".env"
+            if env_path.exists():
+                return env_path
+        return None
+
+    def _load_yaml(self, path: Path) -> None:
+        """Load configuration from YAML file."""
+        if not HAS_YAML:
+            logger.warning("PyYAML not installed — skipping config.yaml")
+            return
+
+        try:
+            with open(path) as f:
+                data = yaml.safe_load(f) or {}  # type: ignore[possibly-undefined]
+
+            self.dashboard_pin = data.get("dashboard_pin", self.dashboard_pin)
+            self.api_token = data.get("api_token", self.api_token)
+            self.host = data.get("host", self.host)
+            self.port = data.get("port", self.port)
+            self.log_level = data.get("log_level", self.log_level).upper()
+
+            logger.info(f"Loaded config from {path}")
+        except Exception as e:
+            logger.error(f"Failed to load config from {path}: {e}")
+
+    def _load_env(self, path: Path) -> None:
+        """Load configuration from .env file."""
+        try:
+            with open(path) as f:
+                for line in f:
+                    line = line.strip()
+                    if line and not line.startswith("#") and "=" in line:
+                        key, value = line.split("=", 1)
+                        key = key.strip()
+                        value = value.strip().strip("'\"")
+
+                        match key:
+                            case "DASHBOARD_PIN":
+                                self.dashboard_pin = value
+                            case "API_TOKEN":
+                                self.api_token = value
+                            case "HOST":
+                                self.host = value
+                            case "PORT":
+                                self.port = int(value)
+                            case "LOG_LEVEL":
+                                self.log_level = value.upper()
+
+            logger.info(f"Loaded config from {path}")
+        except Exception as e:
+            logger.error(f"Failed to load .env from {path}: {e}")
+
+    def _load_from_env(self) -> None:
+        """Load configuration from environment variables (highest priority)."""
+        self.dashboard_pin = os.environ.get("DASHBOARD_PIN", self.dashboard_pin)
+        self.api_token = os.environ.get("API_TOKEN", self.api_token)
+        self.host = os.environ.get("HOST", self.host)
+        try:
+            self.port = int(os.environ.get("PORT", self.port))
+        except ValueError:
+            logger.warning("Invalid PORT environment variable")
+        self.log_level = os.environ.get("LOG_LEVEL", self.log_level).upper()
+
+    def save(self, path: Path | None = None) -> None:
+        """Save configuration to YAML file."""
+        if path is None:
+            path = self._find_config_file() or Path.cwd() / "config.yaml"
+
+        if not HAS_YAML:
+            logger.error("PyYAML not installed — cannot save config")
+            return
+
+        data = {
+            "dashboard_pin": self.dashboard_pin,
+            "api_token": self.api_token,
+            "host": self.host,
+            "port": self.port,
+            "log_level": self.log_level,
+        }
+
+        try:
+            with open(path, "w") as f:
+                yaml.dump(data, f, default_flow_style=False)  # type: ignore[possibly-undefined]
+            logger.info(f"Saved config to {path}")
+        except Exception as e:
+            logger.error(f"Failed to save config to {path}: {e}")
+
+    def to_dict(self) -> dict[str, Any]:
+        """Return configuration as a dictionary (for API responses)."""
+        return {
+            "dashboard_pin": self.dashboard_pin,
+            "api_token": self.api_token,
+            "host": self.host,
+            "port": self.port,
+            "log_level": self.log_level,
+        }
+
+
+# Global config instance
+config = Config()

server/main.py

@@ -17,6 +17,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import HTMLResponse
 
 from .audio_mixer import AudioMixerManager
+from .config import config
 from .media import MediaManager
 from .notifications import NotificationManager, Notification
 from .telemetry import TelemetryManager
@@ -24,9 +25,78 @@ from .telemetry import TelemetryManager
 logger = logging.getLogger("paperdash")
 
 
+# ---------------------------------------------------------------------------
+# Hardware Subsystem Check
+# ---------------------------------------------------------------------------
+
+
+def check_subsystems() -> dict[str, bool]:
+    """Check which hardware subsystems are available."""
+    results: dict[str, bool] = {}
+
+    # Check Voicemeeter
+    try:
+        import voicemeeter_api  # noqa: F401  # type: ignore
+        results["voicemeeter"] = True
+    except ImportError:
+        results["voicemeeter"] = False
+
+    # Check Windows Audio (pycaw)
+    try:
+        import pycaw  # noqa: F401  # type: ignore
+        results["windows_audio"] = True
+    except ImportError:
+        results["windows_audio"] = False
+
+    # Check Windows Media (winsdk)
+    try:
+        import winsdk  # noqa: F401  # type: ignore
+        results["windows_media"] = True
+    except ImportError:
+        results["windows_media"] = False
+
+    # Check HWiNFO (pyhwinfo)
+    try:
+        import pyhwinfo  # noqa: F401  # type: ignore
+        results["hwinfo"] = True
+    except ImportError:
+        results["hwinfo"] = False
+
+    return results
+
+
+# ---------------------------------------------------------------------------
+# Lifespan
+# ---------------------------------------------------------------------------
+
+
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     """Start and stop background managers."""
+    # Load configuration
+    config.load()
+
+    # Configure logging
+    logging.basicConfig(
+        level=getattr(logging, config.log_level, logging.INFO),
+        format="%(asctime)s [%(name)s] %(levelname)s: %(message)s",
+    )
+
+    # Check hardware subsystems
+    subsystems = check_subsystems()
+    app.state.subsystems = subsystems
+    logger.info(f"Hardware subsystems: {subsystems}")
+
+    # Log configuration status
+    if config.dashboard_pin:
+        logger.info("Dashboard PIN is configured")
+    else:
+        logger.warning("Dashboard PIN is NOT configured — WebSocket auth disabled")
+    if config.api_token:
+        logger.info("API token is configured")
+    else:
+        logger.warning("API token is NOT configured — /api/v1/notify disabled")
+
     # Start managers
     app.state.media = MediaManager()
     app.state.audio = AudioMixerManager()
@@ -59,7 +129,7 @@ app = FastAPI(
 
 app.add_middleware(
     CORSMiddleware,
-    allow_origins=["*"],  # Local network only — fine for this use case
+    allow_origins=["*"],  # Local network only — fine for this use case  # noqa: B008
     allow_credentials=True,
     allow_methods=["*"],
     allow_headers=["*"],
@@ -78,7 +148,7 @@ class WebSocketManager:
         self.connections: list[WebSocket] = []
 
     async def connect(self, ws: WebSocket, pin: str) -> bool:
-        expected_pin = os.environ.get("DASHBOARD_PIN", "")
+        expected_pin = config.dashboard_pin
         if not expected_pin or pin != expected_pin:
             await ws.close(code=4001, reason="Invalid PIN")
             return False
@@ -162,7 +232,7 @@ async def handle_client_command(data: dict[str, Any]) -> None:
 
 def _verify_token(authorization: str | None) -> bool:
     """Verify Bearer token from Authorization header."""
-    expected = os.environ.get("API_TOKEN", "")
+    expected = config.api_token
     if not expected:
         return False
     if not authorization or not authorization.startswith("Bearer "):
@@ -178,6 +248,7 @@ async def get_state():
         "audio": app.state.audio.get_state(),
         "telemetry": app.state.telemetry.get_state(),
         "notifications": app.state.notifications.get_active(),
+        "subsystems": app.state.subsystems,
     }
 
 
@@ -195,6 +266,83 @@ async def create_notification(
     return {"id": created.id, "status": "created"}
 
 
+# ---------------------------------------------------------------------------
+# Settings (Protected by API Token)
+# ---------------------------------------------------------------------------
+
+
+class SettingsUpdate:
+    """Settings update payload."""
+
+    def __init__(
+        self,
+        dashboard_pin: str | None = None,
+        api_token: str | None = None,
+        host: str | None = None,
+        port: int | None = None,
+        log_level: str | None = None,
+    ):
+        self.dashboard_pin = dashboard_pin
+        self.api_token = api_token
+        self.host = host
+        self.port = port
+        self.log_level = log_level
+
+
+@app.get("/api/v1/settings")
+async def get_settings(
+    authorization: str | None = None,
+):
+    """Get current settings (requires API token)."""
+    if not _verify_token(authorization):
+        raise HTTPException(status_code=401, detail="Invalid or missing API token")
+    return config.to_dict()
+
+
+@app.post("/api/v1/settings")
+async def update_settings(
+    settings: SettingsUpdate,
+    authorization: str | None = None,
+):
+    """Update settings (requires API token)."""
+    if not _verify_token(authorization):
+        raise HTTPException(status_code=401, detail="Invalid or missing API token")
+
+    if settings.dashboard_pin is not None:
+        config.dashboard_pin = settings.dashboard_pin
+    if settings.api_token is not None:
+        config.api_token = settings.api_token
+    if settings.host is not None:
+        config.host = settings.host
+    if settings.port is not None:
+        config.port = settings.port
+    if settings.log_level is not None:
+        config.log_level = settings.log_level.upper()
+
+    # Save to config file
+    config.save()
+
+    logger.info("Settings updated")
+    return config.to_dict()
+
+
+# ---------------------------------------------------------------------------
+# Hardware Status
+# ---------------------------------------------------------------------------
+
+
+@app.get("/api/v1/status")
+async def get_status():
+    """Get server status including hardware subsystem availability."""
+    return {
+        "subsystems": app.state.subsystems,
+        "config": {
+            "pin_configured": bool(config.dashboard_pin),
+            "token_configured": bool(config.api_token),
+        },
+    }
+
+
 # ---------------------------------------------------------------------------
 # Health
 # ---------------------------------------------------------------------------
@@ -206,16 +354,24 @@ async def health():
 
 
 # ---------------------------------------------------------------------------
-# Client HTML (served directly for Hermit WebView)
+# Client HTML (served directly for WebView)
 # ---------------------------------------------------------------------------
 
 
 @app.get("/", response_class=HTMLResponse)
 async def serve_client():
     """Serve the E-Ink dashboard client."""
-    client_dir = os.path.join(os.path.dirname(__file__), "..", "client")
+    # Try multiple locations for the client files
+    possible_paths = [
+        os.path.join(os.path.dirname(__file__), "..", "client"),
+        os.path.join(os.path.dirname(__file__), "..", "..", "client"),
+        os.path.join(os.path.dirname(__file__), "client"),
+    ]
+
+    for client_dir in possible_paths:
         index_path = os.path.join(client_dir, "index.html")
         if os.path.exists(index_path):
-        with open(index_path, "r") as f:
+            with open(index_path) as f:
                 return f.read()
-    return HTMLResponse("<h1>PaperDash</h1><p>Client files not found in client/</p>")
+
+    return HTMLResponse("<h1>PaperDash</h1><p>Client files not found.</p>")

server/requirements.txt

@@ -2,6 +2,7 @@
 fastapi>=0.100.0
 uvicorn[standard]>=0.23.0
 pydantic>=2.0.0
+pyyaml>=6.0
 
 # Windows APIs
 winsdk>=1.0.0

server/tests/test_config.py

@@ -0,0 +1,134 @@
+"""Tests for the configuration module."""
+
+from __future__ import annotations
+
+import os
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from ..config import Config
+
+
+@pytest.fixture
+def config() -> Config:
+    return Config()
+
+
+class TestConfigDefaults:
+    def test_defaults(self, config: Config) -> None:
+        assert config.dashboard_pin == ""
+        assert config.api_token == ""
+        assert config.host == "0.0.0.0"
+        assert config.port == 8921
+        assert config.log_level == "INFO"
+
+
+class TestConfigLoad:
+    def test_load_from_env(self, config: Config) -> None:
+        os.environ["DASHBOARD_PIN"] = "5678"
+        os.environ["API_TOKEN"] = "test-token"
+        os.environ["HOST"] = "127.0.0.1"
+        os.environ["PORT"] = "9000"
+        os.environ["LOG_LEVEL"] = "DEBUG"
+
+        config.load()
+
+        assert config.dashboard_pin == "5678"
+        assert config.api_token == "test-token"
+        assert config.host == "127.0.0.1"
+        assert config.port == 9000
+        assert config.log_level == "DEBUG"
+
+        # Cleanup
+        del os.environ["DASHBOARD_PIN"]
+        del os.environ["API_TOKEN"]
+        del os.environ["HOST"]
+        del os.environ["PORT"]
+        del os.environ["LOG_LEVEL"]
+
+    def test_load_from_env_file(self, config: Config) -> None:
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".env", delete=False) as f:
+            f.write("DASHBOARD_PIN=1111\n")
+            f.write("API_TOKEN=env-token\n")
+            f.write("# Comment\n")
+            f.write("HOST=0.0.0.0\n")
+            f.write("PORT=8921\n")
+            env_file = f.name
+
+        try:
+            config._load_env(Path(env_file))
+            assert config.dashboard_pin == "1111"
+            assert config.api_token == "env-token"
+        finally:
+            os.unlink(env_file)
+
+    def test_load_from_yaml_file(self, config: Config) -> None:
+        """Test YAML loading (requires PyYAML)."""
+        try:
+            import yaml  # noqa: F401
+        except ImportError:
+            pytest.skip("PyYAML not installed")
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(  # type: ignore[possibly-undefined]
+                {
+                    "dashboard_pin": "2222",
+                    "api_token": "yaml-token",
+                    "host": "0.0.0.0",
+                    "port": 8921,
+                    "log_level": "INFO",
+                },
+                f,
+            )
+            yaml_file = f.name
+
+        try:
+            config._load_yaml(Path(yaml_file))
+            assert config.dashboard_pin == "2222"
+            assert config.api_token == "yaml-token"
+        finally:
+            os.unlink(yaml_file)
+
+
+class TestConfigSave:
+    def test_save_to_yaml(self, config: Config) -> None:
+        """Test YAML saving (requires PyYAML)."""
+        try:
+            import yaml  # noqa: F401
+        except ImportError:
+            pytest.skip("PyYAML not installed")
+
+        config.dashboard_pin = "3333"
+        config.api_token = "save-token"
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            save_path = f.name
+
+        try:
+            config.save(Path(save_path))
+
+            with open(save_path) as f:
+                data = yaml.safe_load(f)  # type: ignore[possibly-undefined]
+
+            assert data["dashboard_pin"] == "3333"
+            assert data["api_token"] == "save-token"
+        finally:
+            os.unlink(save_path)
+
+
+class TestConfigToDict:
+    def test_to_dict(self, config: Config) -> None:
+        config.dashboard_pin = "4444"
+        config.api_token = "dict-token"
+        config.host = "127.0.0.1"
+        config.port = 9000
+        config.log_level = "DEBUG"
+
+        d = config.to_dict()
+        assert d["dashboard_pin"] == "4444"
+        assert d["api_token"] == "dict-token"
+        assert d["host"] == "127.0.0.1"
+        assert d["port"] == 9000
+        assert d["log_level"] == "DEBUG"

server/tests/test_main.py

@@ -92,3 +92,58 @@ class TestNotifyEndpoint:
         assert response.status_code == 401
 
         del os.environ["API_TOKEN"]
+
+
+class TestSettingsEndpoint:
+    def test_get_settings_without_token_returns_401(self, client: TestClient) -> None:
+        response = client.get("/api/v1/settings")
+        assert response.status_code == 401
+
+    def test_get_settings_with_valid_token(self, client: TestClient) -> None:
+        os.environ["API_TOKEN"] = "settings-token"
+
+        response = client.get(
+            "/api/v1/settings",
+            headers={"Authorization": "Bearer settings-token"},
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert "dashboard_pin" in data
+        assert "api_token" in data
+        assert "host" in data
+        assert "port" in data
+
+        del os.environ["API_TOKEN"]
+
+    def test_update_settings(self, client: TestClient) -> None:
+        os.environ["API_TOKEN"] = "update-token"
+
+        response = client.post(
+            "/api/v1/settings",
+            json={
+                "dashboard_pin": "9999",
+                "api_token": "new-token",
+            },
+            headers={"Authorization": "Bearer update-token"},
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert data["dashboard_pin"] == "9999"
+        assert data["api_token"] == "new-token"
+
+        del os.environ["API_TOKEN"]
+
+
+class TestStatusEndpoint:
+    def test_status_returns_subsystems(self, client: TestClient) -> None:
+        # Ensure subsystems are initialized
+        if not hasattr(app.state, "subsystems"):
+            app.state.subsystems = {}
+
+        response = client.get("/api/v1/status")
+        assert response.status_code == 200
+        data = response.json()
+        assert "subsystems" in data
+        assert "config" in data
+        assert "pin_configured" in data["config"]
+        assert "token_configured" in data["config"]