Fix YEARLY recurring CalDAV events only showing on DTSTART year (#179)

* Fix YEARLY recurring CalDAV events only showing on DTSTART year (#170)

Recurring events with RRULE:FREQ=YEARLY only appeared in the calendar
on the year matching DTSTART, not in subsequent years. The list_events
query filtered by , which excludes
recurring events whose original dtend (e.g. 2019-07-22) falls before
the requested window (e.g. 2026).

Fix: split the query into two branches — non-recurring events still
require window overlap, but recurring events (with non-empty RRULE)
are fetched by dtstart < end_dt alone. A new helper,
_expand_rrule_occurrences(), uses dateutil.rrule to expand each
recurring event into individual occurrence dicts within the requested
date range, so YEARLY/WEEKLY/MONTHLY events render correctly across
all years.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* recurrence: compound UIDs, frontend fixes, python-dateutil req, tests

- Replace _expand_rrule_occurrences with _expand_rrule that emits stable
  compound UIDs ({base_uid}::{date_or_datetime}) so the frontend can
  distinguish occurrences from the same series. Non-recurring events
  pass through with is_recurrence=false and series_uid=uid.

- Add _resolve_base_uid() to extract the base series UID from compound
  UIDs — used by PUT/DELETE /api/calendar/events/{uid} and the
  manage_calendar tool so edits/deletes always target the base row.

- Update manage_calendar tool to import and use _resolve_base_uid.

- Frontend _updateEvent / _deleteEvent: detect compound UIDs and
  invalidate localStorage cache after success so stale sibling
  occurrences aren't shown.

- Add python-dateutil to requirements.txt as an explicit dependency.

- Add 14 regression tests in tests/test_calendar_recurrence.py
  covering _resolve_base_uid edge cases, _expand_rrule with
  yearly/weekly/monthly/all-day/bad-rrule, unique UIDs, and
  metadata inheritance.

- Merge upstream's cleaner SQLAlchemy or_/and_ query pattern.

* recurrence: overlapping malformed-RRULE, exclusive end, multi-day crossings

Fix three edge cases in _expand_rrule:

1. Malformed-RRULE fallback now checks window overlap. list_events
   fetches recurring rows with only dtstart < end_dt, so a broken
   old recurring event could appear in unrelated future windows.
   Now fallback returns [] unless the base event's dtstart/dtend
   actually intersect [start, end).

2. Exclusive end boundary. rule.between(start, end, inc=True) was
   inclusive on end, but the route contract and non-recurring SQL
   filter both use [start, end). Added occ_start >= end guard.

3. Multi-day crossings. A recurring occurrence that starts before
   the window but ends inside it was missed (only occ_start was
   checked). Now expands from start - duration and filters by
   occ_start < end AND occ_end > start, matching non-recurring
   overlap behavior.

Tests: +4 tests for these cases (18 total)

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

src/tool_implementations.py

@@ -1952,7 +1952,7 @@ async def do_manage_calendar(content: str, owner: Optional[str] = None) -> Dict:
     """Handle manage_calendar tool calls: list/create/update/delete calendar events (local SQLite)."""
     from datetime import datetime, timedelta
     from core.database import SessionLocal, CalendarCal, CalendarEvent, Note
-    from routes.calendar_routes import _ensure_default_calendar, _parse_dt, _parse_dt_pair, parse_due_for_user
+    from routes.calendar_routes import _ensure_default_calendar, _parse_dt, _parse_dt_pair, parse_due_for_user, _resolve_base_uid
     import uuid as _uuid
 
     try:
@@ -2317,7 +2317,11 @@ async def do_manage_calendar(content: str, owner: Optional[str] = None) -> Dict:
             uid = args.get("uid")
             if not uid:
                 return {"error": "uid is required", "exit_code": 1}
-            ev = _event_query().filter(CalendarEvent.uid == uid).first()
+            try:
+                base_uid = _resolve_base_uid(uid)
+            except ValueError as e:
+                return {"error": str(e), "exit_code": 1}
+            ev = _event_query().filter(CalendarEvent.uid == base_uid).first()
             if not ev:
                 return {"error": f"Event {uid} not found", "exit_code": 1}
             if args.get("summary") is not None:
@@ -2346,7 +2350,11 @@ async def do_manage_calendar(content: str, owner: Optional[str] = None) -> Dict:
             uid = args.get("uid")
             if not uid:
                 return {"error": "uid is required", "exit_code": 1}
-            ev = _event_query().filter(CalendarEvent.uid == uid).first()
+            try:
+                base_uid = _resolve_base_uid(uid)
+            except ValueError as e:
+                return {"error": str(e), "exit_code": 1}
+            ev = _event_query().filter(CalendarEvent.uid == base_uid).first()
             if not ev:
                 return {"error": f"Event {uid} not found", "exit_code": 1}
             db.delete(ev)