feat(shortcuts): add configurable number-key navigation

[luisKisters]

Description

Adds configurable number-key navigation for tasks and pane tabs.

• Uses Command+1-9 for pane and conversation tabs on macOS, preserving the familiar tab
  navigation behavior.
• Uses Control+1-9 for sidebar tasks on macOS. Windows and Linux use Mod+1-9 for tabs and
  Alt+1-9 for tasks to avoid conflicts.
• Makes every task and tab position individually rebindable or disableable in Settings.
• Forwards configured bindings through terminals and embedded browser webviews, including
  arbitrary non-digit rebindings.
• Shows delayed keycap hints while the family modifier is held, then removes the hint overlay as
  soon as a shortcut is used so the gradient does not linger during navigation.
• Keeps task numbering aligned with the rendered sidebar order.
• Debounces each action independently and adds focused regression coverage.

Related issues

No issue linked.

Testing

• pnpm --filter @emdash/emdash-desktop exec vitest run --project node src/shared/shortcuts.test.ts src/main/core/browser/browser-webcontents-registry.test.ts src/renderer/lib/hooks/use-number-hotkeys.test.ts (25 tests passed)
• focused oxlint across all changed TypeScript files
• focused oxfmt --check across all changed TypeScript files
• pnpm --filter @emdash/emdash-desktop exec tsgo --noEmit
• git diff --check origin/main...HEAD
• manual verification in an isolated development database

Screenshot/Recording

Task & Conversation switching

Screen.Recording.2026-07-12.at.16.36.58.mov

Configurable task and tab bindings

Checklist

• I kept this PR small and focused
• I ran a self-review before opening this PR
• I ran the relevant local checks or explained why not
• I updated documentation and PR evidence where behavior changed
• I added or updated tests when behavior changed
• I only added comments where the logic is not obvious
• I used Conventional Commits for commit messages and the PR title

[greptile-apps]

Greptile Summary

This PR adds configurable number-key navigation for tasks and tabs. The main changes are:

• New per-position shortcut settings for tab and task jumps.
• Browser webview and terminal forwarding for number shortcuts.
• Sidebar and tab-bar hint overlays while the family modifier is held.
• Shared debounce handling and focused tests for shortcut behavior.

Confidence Score: 5/5

The changed flow looks mergeable after small cleanup to hint state and terminal conflict behavior.

• Core navigation targets use the same task and tab ordering as the displayed hints.
• Browser forwarding keeps the source browser id and routes tab shortcuts to the owning pane.
• Terminal dispatch can pick the wrong action when two number shortcuts share one key.
• Hint visibility can stay true after changing the reveal modifier.

apps/emdash-desktop/src/renderer/lib/hooks/use-number-hotkeys.ts; apps/emdash-desktop/src/renderer/lib/hooks/use-modifier-held.ts

Important Files Changed

Filename	Overview
apps/emdash-desktop/src/main/core/browser/browser-webcontents-registry.ts	Adds browser webContents forwarding for number shortcuts and modifier state.
apps/emdash-desktop/src/renderer/lib/hooks/use-number-hotkeys.ts	Adds shared number shortcut binding, debounce, and terminal dispatch helpers.
apps/emdash-desktop/src/renderer/lib/hooks/use-modifier-held.ts	Adds delayed modifier-held tracking for shortcut hint overlays.
apps/emdash-desktop/src/renderer/features/sidebar/sidebar-store.ts	Adds a single numbered task order for shortcuts and hint badges.
apps/emdash-desktop/src/shared/shortcuts.ts	Adds task and tab number shortcut definitions and ordered key arrays.

Prompt To Fix All With AI

Fix the following 2 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 2
apps/emdash-desktop/src/renderer/lib/hooks/use-number-hotkeys.ts:45
**Terminal Dispatch Uses Global Order**

When a task number shortcut and a tab number shortcut are rebound to the same key, terminal input goes through this `dispatch: 'first'` path instead of the normal focused document handler. The first enabled global registration wins by manager insertion order, so a focused terminal can navigate to a sidebar task instead of switching the focused pane tab, or the reverse.

### Issue 2 of 2
apps/emdash-desktop/src/renderer/lib/hooks/use-modifier-held.ts:97-104
**Held State Survives Rebinding**

When the configured reveal modifier changes while hints are visible, the old effect cleanup removes listeners and clears the timer but leaves `held` as `true`. The next shortcut family can show its hint overlay immediately even though the new modifier was never held.

```suggestion
    return () => {
      window.removeEventListener('keydown', onKeyDown, true);
      window.removeEventListener('keyup', onKeyUp, true);
      window.removeEventListener('blur', cancel);
      stopForwardedModifier();
      stopForwardedShortcut();
      if (timer !== null) window.clearTimeout(timer);
      setHeld(false);
    };
```

_{Reviews (1): Last reviewed commit: "fix(shortcuts): refine number navigation..." | Re-trigger Greptile}