feat(bridge): render markdown in the Windows tray meeting-summary window

[Vortiago]

Why

The Windows tray bridge's per-meeting window showed the LLM summary in a read-only TextBox, so the raw markdown (## Decisions, - bullet, **owner**, `api/tap`) appeared as literal markup — hard to read. The backend serves the summary as raw markdown (it never pre-renders HTML), and the web dashboard already renders a small, deliberately-minimal markdown subset. This brings the same readability to the tray window.

What

• SummaryMarkdown (TapScribe.Bridge.Core, net10.0, no WinForms): a pure parser of the same subset the web renderMarkdown/_inlineMd supports — #–###### headings, -/* bullets, 1./1) numbered (renumbered sequentially), fenced ``` code blocks (verbatim), paragraphs, and inline `code`/`bold`/`italic` (flat, no nesting). Includes a `Plain()` wrapper for non-markdown status/failure lines. Exhaustively unit-tested on the Linux/CI cross-platform job.
• SummaryRichText (TapScribe.TrayBridge): paints the block model onto a read-only RichTextBox with native styled runs — heading fonts, bullet/number prefixes, bold/italic, monospace code. No new dependency, no WebView2 runtime (a plain static helper, not a Control subclass, so it never trips WFO1000).
• MeetingFormView gains a BodyIsMarkdown signal (true only for the Done summary) so the dumb WinForms shell routes markdown-vs-plain explicitly and a raw recorder error line can't be reinterpreted as markdown.
• MeetingForm: TextBox → RichTextBox; Copy now yields the raw markdown source (clean to paste into markdown-aware tools); the per-tick Apply re-renders only when the body actually changes.

Design notes

• The markdown subset deliberately mirrors the web renderer (tapscribe/web/js/templates.js) so the two stay in conceptual sync; they remain independent JS/C# implementations (no shared code across the boundary).
• Parsing lives in the cross-platform, unit-tested Core; the WinForms shell stays a dumb projection — matching the PipelineView/StatusView/MeetingFormView pattern.
• RichTextBox chosen over WebView2 to avoid a runtime dependency for a deliberately tiny markdown subset.

Testing

• dotnet test tests/TapScribe.Bridge.Core.Tests — 250 pass (new SummaryMarkdownTests + MeetingFormView BodyIsMarkdown assertions; existing tests unchanged). Mirrors the CI ubuntu cross-platform job.
• dotnet build TapScribe.WindowsTrayBridge.slnx -c Release -p:EnableWindowsTargeting=true — clean, 0 warnings (mirrors the Windows compile job).
• Reviewed with /simplify (reuse/simplification/efficiency/altitude) and /code-review (xhigh).
• ⚠️ Manual Windows check still needed (GUI can't run on the Linux dev box): end a meeting / re-open a past meeting → summary shows formatted headings, bullets, numbered items, bold/italic, monospace code; Copy puts raw markdown on the clipboard.

🤖 Generated with Claude Code