[davior]

Problem

Selecting part of a note before opening Export → Video (MP4) was meant to render only the selection (added in #200). It didn't work, for two reasons:

1. Footer showed the whole note. The dialog's /video/estimate request never sent the selection, so "N segments · N characters to narrate · about Xm" always described the full note.
2. The render itself was empty. The editor sent the selection as Markdown (getEditorSelectionMarkdown), but the segmenter does json.loads on BlockNote JSON and treats anything else as an empty note. A selected render had only the title card and bumpers, or failed with "This note has no text or media".

Changes

• EditorView.tsx: sends editor.getSelection().blocks as BlockNote JSON, the same form as the stored note. Diagram rasterising walks the selected blocks directly.
• videoGen.ts / VideoGenModal.tsx: estimate() takes selectedContent, the estimate re-runs when it changes, and the footer starts with "Selection only ·" when a selection is in effect.
• schemas.py: VideoRenderRequest.selected_content must be a JSON array of blocks or the request gets a 422, so it can no longer silently render nothing. An empty selection ("" or []) means the whole note.

The selection works at block level, so a partly selected paragraph renders in full. That matches how segments are built.

Testing

• New backend/tests/test_video_selection.py:
  • estimating a selection gives the same result as a note that holds only those blocks;
  • a selection estimates smaller than the whole note;
  • Markdown or non-array input is refused;
  • an empty selection means the whole note.
• Backend: 1190 passed. Frontend: tsc --noEmit clean, vitest 204 passed.

🤖 Generated with Claude Code

https://claude.ai/code/session_01QiJqUAvLhqbSCdkPRDbh7J

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