feat(api): add video generation endpoint

Add POST /sdapi/v1/video plus GET /sdapi/v1/video/models and
GET /sdapi/v1/video/file. The generation body is extracted from the
gradio handler into a keyword-only core, video_run.run, which returns a
structured result and raises typed errors; the positional generate
signature is unchanged and now adapts to the core. Omitting engine and
model drives the currently loaded checkpoint when it is video-capable,
which covers models loaded from local folders without a registry entry.

- registry helpers in models_def (find, engines, pipeline_classes,
  workflow_for_class); validate_pipeline reuses the shared class set
- modular pipes stamp their workflow so out-of-registry loads dispatch
  onto the modular branch
- disk switches (mp4_*) and wire switches (send_*) are independent;
  artifacts above the base64 cap fall back to path plus the file route,
  which is jailed to the video output directory and serves video/mp4
  with range support
- always-on video scripts get bootstrapped default args, matching the
  txt2img handler; missing bootstrap raised a TypeError per frame
- checkpoint overrides are rejected with a pointer to the checkpoint
  endpoint; unknown engine, model and sampler names return 404 with the
  valid choices
- cli/api-video.py client, test/test-video-api.py suite and a
  full-test.sh entry; video mimetypes registered; rate-limit cost set
- remove the unreferenced video_ui.run_video dispatcher

modules/api/api.py

@@ -6,7 +6,7 @@ from fastapi.security import HTTPBasic, HTTPBasicCredentials
 from fastapi.exceptions import HTTPException
 from modules import errors, shared, paths
 from modules.logger import log
-from modules.api import models, endpoints, script, helpers, server, generate, process, control, docs, gpu
+from modules.api import models, endpoints, script, helpers, server, generate, process, control, video, docs, gpu
 
 
 errors.install()
@@ -33,6 +33,7 @@ class Api:
         self.generate = generate.APIGenerate(queue_lock)
         self.process = process.APIProcess(queue_lock)
         self.control = control.APIControl(queue_lock)
+        self.video = video.APIVideo(queue_lock)
         # compatibility api
         self.text2imgapi = self.generate.post_text2img
         self.img2imgapi = self.generate.post_img2img
@@ -68,6 +69,7 @@ class Api:
         self.add_api_route("/sdapi/v1/txt2img", self.generate.post_text2img, methods=["POST"], response_model=models.ResTxt2Img, tags=["Generation"])
         self.add_api_route("/sdapi/v1/img2img", self.generate.post_img2img, methods=["POST"], response_model=models.ResImg2Img, tags=["Generation"])
         self.add_api_route("/sdapi/v1/control", self.control.post_control, methods=["POST"], response_model=control.ResControl, tags=["Generation"])
+        self.add_api_route("/sdapi/v1/video", self.video.post_video, methods=["POST"], response_model=video.ResVideo, tags=["Generation"])
         self.add_api_route("/sdapi/v1/process", self.process.extras_single_image_api, methods=["POST"], response_model=models.ResProcessImage, tags=["Processing"])
         self.add_api_route("/sdapi/v1/extra-single-image", self.process.extras_single_image_api, methods=["POST"], response_model=models.ResProcessImage, tags=["Processing"])
         self.add_api_route("/sdapi/v1/process-batch", self.process.extras_batch_images_api, methods=["POST"], response_model=models.ResProcessBatch, tags=["Processing"])
@@ -104,9 +106,11 @@ class Api:
         self.add_api_route("/sdapi/v1/extra-network-detail", endpoints.get_extra_network_detail, methods=["GET"], response_model=models.ItemExtraNetworkFull, tags=["Enumerators"])
         self.add_api_route("/sdapi/v1/extra-network-details", endpoints.get_extra_network_details, methods=["GET"], response_model=models.ResExtraNetworkDetails, tags=["Enumerators"])
         self.add_api_route("/sdapi/v1/unets", endpoints.get_unets, methods=["GET"], response_model=list[models.ItemUNet], tags=["Enumerators"])
+        self.add_api_route("/sdapi/v1/video/models", self.video.get_video_models, methods=["GET"], response_model=list[video.ItemVideoModel], tags=["Enumerators"])
 
         # functional api
         self.add_api_route("/sdapi/v1/file", endpoints.get_file, methods=["GET"], tags=["Functional"])
+        self.add_api_route("/sdapi/v1/video/file", self.video.get_video_file, methods=["GET"], tags=["Functional"])
         self.add_api_route("/sdapi/v1/delete-image", endpoints.get_deleteimage, methods=["DELETE"], tags=["Functional"])
         self.add_api_route("/sdapi/v1/delete-file", endpoints.get_deletefile, methods=["DELETE"], tags=["Functional"])
         self.add_api_route("/sdapi/v1/png-info", endpoints.get_pnginfo, methods=["GET"], response_model=models.ResImageInfo, tags=["Functional"])