fal: ?activity= OpenAPI documents drop indexed endpoints (veo3.1, kling, sora-2) #605

Problem

GET /v1/openapi/fal?activity={activity} leaves out endpoints that GET /v1/schemas/fal lists for that activity. Each missing endpoint has no input_/output_ schema and is not in the endpoint_id enum. The single-endpoint route still serves its schema, for example GET /v1/schemas/fal/video/fal-ai/veo3.1.

Examples that are missing: fal-ai/veo3.1, fal-ai/veo3.1/image-to-video, fal-ai/kling-video/v2.1/master/image-to-video, fal-ai/sora-2/image-to-video, bytedance/seedance-2.0/text-to-video, fal-ai/aura-flow, fal-ai/diffrhythm.

Some fal endpoints that TanStack AI uses are not in /v1/schemas/fal at all: fal-ai/whisper, fal-ai/flux-2-trainer, fal-ai/hunyuan3d/v2, fal-ai/hyper3d/rodin.

Ask

1. Put every endpoint in /v1/schemas/fal for an activity into that activity's OpenAPI document, with its input_ and output_ schemas and x-modelschemas-model.
2. Find out why the endpoints in the second list are not indexed, and index them if fal lists them.

Acceptance

• For each fal activity, the x-modelschemas-model ids in ?activity= equal the ids in /v1/schemas/fal.
• fal-ai/veo3.1 and fal-ai/whisper each have an input and output schema in their activity document.

TanStack AI generates per-activity fal types from these documents (TanStack/ai#2104). Missing endpoints fall back to untyped options there.