Task: Fix video intent rendering as image confirmation

Identity

Normalize the server's public generation-option payload for the Electron/Main-to-Renderer shared design contract.
Support both canonical client options (value/disabled) and the current server configuration shape (id or seconds/enabled) without changing the Renderer API.
Add a regression proving a video Quote retains its medium and exposes selectable 2/6 second durations.

The raw trace proves this run reached medium=video and bailian_video_direct_v1; the UI failure was caused by option-shape loss, not by a server image decision.
Preserve existing image and legacy conversation compatibility.
Do not expose provider credentials or change the HTTP API; normalization belongs at the Electron adapter boundary.

Added a typed adapter normalizer that maps value/id/seconds to the shared value field and maps enabled=false to disabled=true (while retaining canonical payloads).
The Renderer now receives video durations as numeric selectable options, so the duration control and video confirmation validation can work with the live server response.
Added a regression test using the server-shaped video options and asserting the mapped video medium, model, and durations.

pnpm exec vitest run tests/unit/works-square-design-workspace.test.ts — 32 passed.
pnpm exec vitest run tests/unit/image-canvas-page.test.tsx tests/unit/works-square-design-workspace.test.ts — 79 passed.
pnpm run typecheck — passed.
pnpm exec eslint electron/image-workspace/works-square-workspace.ts tests/unit/works-square-design-workspace.test.ts — passed.
pnpm run build:vite — passed (existing chunk-size and dynamic-import warnings only).
git diff --check — passed (only the repository's CRLF conversion warnings).

Ship this client commit with the server intent-guard commit; run the packaged desktop smoke test against a live video Quote.
A future API contract cleanup may make the server publish canonical option names directly, but the adapter normalizer is the compatibility boundary for now.