Calendar: event dots + configurable day-cell click in Day Panel

[h4yfans]

Summary

• Calendar tab — Day Panel mini-calendar now shows dots driven by event counts (from useCalendarRange) instead of the journal heatmap. Other tabs keep the journal heatmap unchanged.
• Configurable day-cell click — clicking a day in the Day Panel now routes through a new user preference:
  • Global setting: journal (default) or calendar.
  • Calendar-page override: inherit / journal / calendar. Default calendar so today's behavior is preserved when the Calendar tab is active.
• Clicking a day from a non-calendar tab with global = calendar opens a Calendar tab and sets the anchor date.
• New Calendar section in Settings (side nav → Workspace → below Tasks) with two selects.

Why

The right-sidebar Day Panel is useful on every tab, but on the Calendar tab the journal heatmap dots don't match what the user is actually looking at. The user also wanted control over where a day click leads — Journal for note-centric users, Calendar for calendar-centric users — with a per-page override so the Calendar tab can always mean "stay in Calendar."

What changed

Contracts / RPC

• packages/contracts/src/settings-schemas.ts — adds CalendarSettingsSchema + CALENDAR_SETTINGS_DEFAULTS (distinct from existing calendar.google group).
• packages/contracts/src/ipc-channels.ts — adds GET_CALENDAR_SETTINGS / SET_CALENDAR_SETTINGS.
• packages/rpc/src/settings.ts — exposes the new methods on the generated RPC API.

Main (Electron)

• apps/desktop/src/main/ipc/settings-handlers.ts — registers + tears down the two handlers using existing readGroupSettings / writeGroupSettings helpers with key 'calendar'.

Renderer

• apps/desktop/src/renderer/src/hooks/use-calendar-preferences.ts — new hook + pure resolveDayCellClickBehavior(settings, isCalendarTabActive) helper.
• apps/desktop/src/renderer/src/hooks/use-calendar-preferences.test.ts — 7 unit tests covering the full truth table (global × override × tab-active).
• apps/desktop/src/renderer/src/pages/settings/calendar-section.tsx — new settings UI (two Select rows).
• apps/desktop/src/renderer/src/pages/settings.tsx — adds Calendar nav entry (uses existing CalendarDays icon).
• apps/desktop/src/renderer/src/contexts/settings-modal-context.tsx — extends SettingsSection union with 'calendar'.
• apps/desktop/src/renderer/src/components/day-panel/global-day-panel.tsx — queries the visible month via useCalendarRange, swaps activity source based on isCalendarTabActive, and routes clicks + today through the resolver. Opens a new Calendar tab when needed.

Tests

• apps/desktop/tests/setup-dom.ts — adds getCalendarSettings / setCalendarSettings to the window.api.settings mock so existing tests that touch the Day Panel keep working.

Generated-file churn (flagging for reviewer)

apps/desktop/src/main/ipc/generated-ipc-invoke-map.ts and apps/desktop/src/preload/generated-rpc.ts have a ~3100-line drop that is not my hand edit. Running pnpm ipc:generate produced a different format than what was stored in the repo, suggesting pre-existing drift between the committed files and the current generator output. pnpm ipc:check passes after regeneration. Happy to revert if there's a preferred CI path (e.g., regenerate in a follow-up) — flagging so it isn't a surprise in review.

Test plan

• pnpm typecheck:node + pnpm typecheck:web — both clean.
• pnpm ipc:check — up to date.
• pnpm exec vitest run — 7139 pass. The 3 failures in calendar-page.test.tsx are pre-existing (window.api.showContextMenu is not a function — unrelated to this PR).
• New resolver tests — 7 / 7 pass.
• Manual smoke (pnpm dev):
  • Calendar tab + Day Panel open → dots reflect event counts per day; click a day → stays in calendar, anchor moves.
  • Notes tab + Day Panel open → dots reflect journal activity (unchanged); click a day → opens Journal at that date.
  • Change override to journal in Settings → click day on Calendar tab opens Journal.
  • Change global to calendar → click day from Notes tab opens a Calendar tab.
  • Toggle settings live → Day Panel updates without reload (via onSettingsChanged broadcast).
• E2E (follow-up — planned specs: right-sidebar-event-dots.spec.ts, sidebar-day-click-behavior.spec.ts). Not included here to keep this PR focused; remember npx electron-vite build before pnpm test:e2e per CLAUDE.md.

Open design question

Event dots and journal dots currently share the ACTIVITY_DOT_COLORS ramp (green-family, quantized 0–4). Consider adding a distinct ramp (e.g., tint/blue) for events so the swap is visually obvious. Trivial to add a dotColorVariant prop on DatePickerCalendar if desired.