Human idea capture surface

Where and how the human captures an idea into a project's inbox, aligned with the design frame.

Status

Draft (companion to the idea capture endpoint in POST /api/v1/projects/{id}/ideas).

Context

The idea capture backend lands an idea as a needs-action signal in a project's inbox. A human surface is still needed: a place to write the idea, choose its project, and see it triaged, without leaving the mailbox model.

Decision

• The capture entry point is a single glyph button in the inbox/project header control row, opening a sheet (phone) or the aside (desktop) per the one- surface rule.
• The sheet holds one 640px column with a summary field and an optional note, sized by the pointer like every other form.
• On submit the idea is posted to the project's endpoint and appears in the inbox without a reload; the composer clears and focus returns to the button.
• An empty summary is refused client-side and server-side.
• Triage reuses the existing inbox verbs: read, mark done, and (later) promote to a knowledge base page.

Consequences

• No new screen: capture is an aside/sheet over the inbox or project stage.
• Keeps the frame stable and avoids a dedicated route.
• The button is the only new control; all sizing follows the design tokens.