feat(edit): event editing — shared form, scoped recurring writes, recurrence picker (v1.3)

The create form (v1.2) now edits: a pencil on the detail screen (writable
calendars only, contextual WRITE upgrade like delete) opens it prefilled via
EventDetail.toEditForm; populated sections always show, the calendar is
fixed, and a dirty-check writes only changed columns (pristine saves are
no-ops). Saving a dirty recurring event parks in SaveUiState.AwaitingScope
and asks how far the change reaches (Google model): "only this event" =
modified-occurrence exception via CONTENT_EXCEPTION_URI (empty optionals as
explicit NULLs since the provider clones the parent row), "this and all
following" = series split (insert new event first, then truncate), "all
events" = series-row update with the time delta applied to the series
DTSTART. A changed rule drops the exception option. Delete gained the same
middle scope.

Recurrence: EventForm.rrule + SimpleRecurrence (FREQ/INTERVAL/UNTIL/COUNT +
weekly BYDAY with locale-ordered weekday toggles) behind a picker on create
and edit; unrepresentable rules render humanized (shared ui/common
RecurrenceText) and survive verbatim. UNTIL validation flags rules ending
before the event starts.

Provider lessons baked in (verified on-device via adb probes): instance
caches regenerate only from an update's own values, so truncation sends the
full time-column set (truncateSeries) — RRULE-only updates left a stale
duplicate occurrence on the split day; UNTIL is written as the local end of
day in UTC (toRRule(zone), previousLocalDayEndUtcMillis) so UTC+x zones
can't leak an extra day. Reminder edits reconcile against actual provider
rows, keeping untouched rows' methods.

Tests: RecurrenceTest (parse/render/round-trip, truncation), update/exception
mapper paths, repository pass-throughs, prefill + populatedFields, raw-title
mapper.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -64,9 +64,35 @@ guide here, not a contract — scope per slice is decided as we go.
 | v1.1 | Write foundation — `WRITE_CALENDAR`, read-only-calendar detection, delete (series + single occurrence) | complete (shipped 2026-06-11) |
 | v1.2 | Create event — form, FAB, last-used-calendar preselect | complete (shipped 2026-06-11) |
 | v1.2.1 | Form polish after on-device review — card design system, optional fields + settings defaults, OptionCard dialogs, expressive motion | complete (shipped 2026-06-11) |
-| v1.3 | Edit event — shared form, series edit, reminders, simple recurrence picker | planned |
+| v1.3 | Edit event — shared form, scoped recurring writes (this / following / all), recurrence picker | complete (shipped 2026-06-11) |
+| v1.4 | Reminder notifications — see below | planned |
 | v2.0 | Quick-add, occurrence edit, conflict dialog, polish, release | planned |
 
+## v1.4 — Reminder Notifications
+
+**Essential**, not nice-to-have: Calendula targets users for whom it is their
+*only* calendar app, so reminder delivery can't be delegated to Google/OEM
+Calendar. The calendar provider schedules reminders and broadcasts
+`android.intent.action.EVENT_REMINDER`, but it does **not** post the visible
+notification — a calendar app must. We become that app (the Etar model).
+
+Scope:
+- Manifest-registered `BroadcastReceiver` for `EVENT_REMINDER`
+  (data scheme `content://com.android.calendar`) — wakes us at reminder time,
+  no foreground service.
+- Read `CalendarContract.CalendarAlerts` / `Reminders`, filter to
+  `METHOD_ALERT` / `METHOD_DEFAULT` (skip `METHOD_EMAIL`); post on a dedicated
+  notification channel; tap opens event detail.
+- `POST_NOTIFICATIONS` runtime permission (API 33+) — requested in onboarding.
+- Onboarding step: (a) request `POST_NOTIFICATIONS`, (b) in-app reminders
+  toggle, **default ON**, with copy warning that a second calendar app with
+  notifications on will cause duplicate reminders. Mirrored into Settings
+  (reversible).
+
+Deliberately deferred (add only if needed):
+- Snooze / dismiss notification actions (Etar has them)
+- Battery-optimization exemption prompt for delivery reliability
+
 ## v3.0 — Power-User Features
 
 - Home-screen widget