Right-click context menus

Hover-only toolbars on code blocks, tables, and mermaid diagrams have been replaced with native-style right-click context menus. The chrome is quieter, the actions are still discoverable (right-click is the universal "what can I do here?" gesture), and there's room to grow the menus without crowding the visible UI.

Where they're wired

Surface	Menu items
Code block (<pre>)	Copy · Download as file · Export as PNG · — · Show / Hide line numbers
Table (.mid-table)	Copy as Markdown · Download CSV · Download JSON · — · Reset sort (when active)
Mermaid (.mermaid)	Copy SVG · Download SVG · Download PNG
File-tree row (.mid-tree-item, files only)	Open · Reveal in Finder
Note row (.mid-note-row)	Open · Rename… · — · Delete
Document body (.mid-preview)	Copy text · — · Export Markdown / HTML / PDF / PNG / Plain text

Right-click on any nested element bubbles to the closest matching surface — e.g. right-click on a table cell opens the table menu, right-click on a code-block keyword opens the code menu. The body menu only fires when no other surface claimed the event.

What's still visible

• Code blocks keep the language pill (top-left) — visual cue, not an action.
• Tables > 5 rows keep a small filter+counter chip in the top-right (the filter is functional and not duplicated by the right-click menu).
• Sortable headers still cycle on click (asc → desc → unsorted).

Smaller tables (≤ 5 rows) hide the chip entirely so prose flows uninterrupted.

Implementation

openContextMenu(items, x, y) builds an absolutely-positioned .mid-context-menu overlay with a one-frame fade-in animation, auto-clamps to viewport edges, closes on outside-click or Esc, and routes each item to its action. Items are typed { icon?, label, kbd?, action?, separator?, disabled? }.

No main-process roundtrip — the menu is purely renderer-side, so it inherits the active theme tokens and animates with the rest of the chrome.

Files

• apps/electron/renderer/renderer.ts — openContextMenu, MenuItem, attachCodeBlockToolbar/attachTableTools/attachMermaidToolbar rewritten to register contextmenu listeners; renameNote added; document-level body fallback handler.
• apps/electron/renderer/renderer.css — .mid-context-menu, .mid-context-item, .mid-context-sep, .mid-context-kbd styles. .mid-table-chip replaces the old full-width .mid-table-toolbar.

Verifying

1. Right-click a code block → menu appears with Copy / Download / Export PNG / line-numbers toggle.
2. Right-click a table → menu offers Copy as MD / CSV / JSON. Click the column header to sort, then right-click → Reset sort is enabled.
3. Right-click a mermaid diagram → SVG / SVG download / PNG download.
4. Right-click a file in the sidebar tree → Open / Reveal in Finder.
5. Right-click a note row → Open / Rename / Delete.
6. Right-click empty space in the preview → Copy text + 5 export formats.
7. Esc closes the menu without firing any action.