Week view flexibility: configurable day count, layout, and a CalDAV task list

- Day count (2-10, was fixed at 7) -- 5 days trims the weekend clutter
  without losing the grid format.
- Layout choice: days side by side (original behavior) or stacked
  vertically as full agenda-style sections (reuses _draw_agenda_day,
  same approach _build_today_tomorrow already used for a fixed 2 days).
- Optional task list (CalDAV VTODO collections only -- a plain ICS
  subscription doesn't meaningfully have one) that takes the space of
  one day slot instead of adding an extra one. Same owner-controls-
  their-own-data permission split as calendar sources: only the
  calendar's owner can point a frame's task list at it, but anyone
  linked to the frame can clear it.

Browse-offset paging now moves by N days (was hardcoded to weeks),
identical to the old behavior when days=7. Changing the day count
resets the browse offset, same reasoning as changing views already did.

server/app/routers/api_frames.py

@@ -44,6 +44,7 @@ from .common import (
     calendar_sources_for_frame,
     fetch_source_and_faces,
     get_or_refresh_calendar_events,
+    get_or_refresh_tasks,
     get_or_refresh_weather,
     immich_client_for,
     immich_creds,
@@ -101,8 +102,11 @@ def api_config_save(
     calendar_view: str | None = Form(None),
     calendar_photo_inlay: bool | None = Form(None),
     calendar_week_start: int | None = Form(None),
+    calendar_week_days: int | None = Form(None),
+    calendar_week_layout: str | None = Form(None),
     calendar_weather_enabled: bool | None = Form(None),
     calendar_weather_units: str | None = Form(None),
+    calendar_tasks_enabled: bool | None = Form(None),
     frame: Frame = Depends(require_frame_control),
     db: Session = Depends(get_db),
 ):
@@ -180,6 +184,16 @@ def api_config_save(
             cfg.calendar_photo_inlay = calendar_photo_inlay
         if calendar_week_start is not None:
             cfg.calendar_week_start = max(0, min(6, calendar_week_start))
+        if calendar_week_days is not None:
+            new_days = max(2, min(10, calendar_week_days))
+            if new_days != cfg.calendar_week_days:
+                # A stale offset counts a different-sized page under the
+                # old day count -- same reasoning as calendar_view's own
+                # reset below.
+                cfg.calendar_browse_offset = 0
+            cfg.calendar_week_days = new_days
+        if calendar_week_layout is not None:
+            cfg.calendar_week_layout = calendar_week_layout if calendar_week_layout in ("horizontal", "vertical") else "horizontal"
         if calendar_weather_enabled is not None:
             cfg.calendar_weather_enabled = calendar_weather_enabled
         if calendar_weather_units is not None and calendar_weather_units in ("fahrenheit", "celsius"):
@@ -188,6 +202,8 @@ def api_config_save(
                 # rather than showing stale numbers under a new unit label.
                 cfg.calendar_weather_checked_at = 0.0
             cfg.calendar_weather_units = calendar_weather_units
+        if calendar_tasks_enabled is not None:
+            cfg.calendar_tasks_enabled = calendar_tasks_enabled
         cfg.stats_config_saves += 1
     return {"status": "saved"}
 
@@ -548,15 +564,51 @@ def api_preview_calendar(frame: Frame = Depends(require_frame_view), db: Session
     photo_inlay = _calendar_photo_inlay(frame, db)
     view = frame.calendar_view if frame.calendar_view in calendar_render.CALENDAR_VIEWS else "agenda"
     weather_cities = get_or_refresh_weather(db, frame)
+    tasks = get_or_refresh_tasks(db, frame) if (view == "week" and frame.calendar_tasks_enabled) else None
     png = calendar_render.render_calendar_preview_png(
         events, view=view, browse_offset=frame.calendar_browse_offset, orientation=frame.orientation,
         palette_rgb=frame.palette_rgb, timezone=frame.timezone, photo_inlay=photo_inlay, fetch_summary=summary,
         week_start=frame.calendar_week_start,
         weather_cities=weather_cities, weather_units=frame.calendar_weather_units,
+        week_days=frame.calendar_week_days, week_layout=frame.calendar_week_layout, tasks=tasks,
     )
     return Response(content=png, media_type="image/png")
 
 
+class TasksSourceRequest(BaseModel):
+    calendar_key: str | None  # None clears the source
+
+
+@router.post("/api/frames/{frame_id}/tasks-source")
+def api_tasks_source(
+    body: TasksSourceRequest,
+    request: Request,
+    frame: Frame = Depends(require_frame_view),
+    db: Session = Depends(get_db),
+):
+    """Points this frame's week-view task list at one of the calling
+    user's own CalDAV calendars -- same owner-controls-their-own-data
+    permission split as calendar-select's included=True, since this is
+    volunteering personal calendar data, not a frame-wide display
+    setting a controller should get to pick on someone else's behalf.
+    None clears the source; clearing (unlike setting) isn't
+    ownership-gated -- like muting a shared calendar, anyone linked to
+    the frame can turn off a task list they'd rather not see, but only
+    its owner can point the frame at one of their calendars to begin
+    with."""
+    user = require_user_api(request, db)
+    with frame_locked(db, frame.id) as cfg:
+        if body.calendar_key is None:
+            cfg.calendar_tasks_user_id = None
+            cfg.calendar_tasks_calendar_key = None
+            cfg.calendar_tasks_cached = None
+        else:
+            cfg.calendar_tasks_user_id = user.id
+            cfg.calendar_tasks_calendar_key = body.calendar_key
+        cfg.calendar_tasks_checked_at = 0.0  # pick up the change promptly
+    return {"status": "saved", "calendar_key": body.calendar_key}
+
+
 class WeatherCityAddRequest(BaseModel):
     name: str