Calendar mode polish batch + Today & Tomorrow view

Responds to post-launch feedback on calendar mode: configurable
week-start day for week/month views, crisper non-antialiased text
(threshold-masked instead of drawn straight, so Floyd-Steinberg
dithering doesn't speckle glyph edges), a color-coded/proportionally
filled battery icon on the manage overlay, word-wrapped placeholder
text so "Calendar isn't set up yet" no longer clips in portrait, photo
inlay support extended from agenda-only to every view, and a fix so
manage-overlay face labels reposition correctly when a photo inlay is
active (they previously assumed the photo filled the whole canvas).

Also adds a fourth calendar view, "Today & Tomorrow" -- a two-day
agenda that reuses the same per-day row-layout helper the single-day
agenda view already has.

server/app/migration.py

@@ -100,6 +100,16 @@ def _migration_7(conn) -> None:
     conn.execute(text("ALTER TABLE frames ADD COLUMN calendar_fetch_summary TEXT NOT NULL DEFAULT ''"))
 
 
+def _migration_8(conn) -> None:
+    """Configurable week-start day for calendar mode's week/month views
+    (0=Monday..6=Sunday, matching Python's date.weekday()/calendar.Calendar
+    convention exactly -- no translation needed at render time). Default 0
+    (Monday) matches calendar_render.py's previous hardcoded behavior, so
+    this is a no-op for every existing frame until changed."""
+    conn.execute(text("ALTER TABLE frames ADD COLUMN calendar_week_start INTEGER NOT NULL DEFAULT 0"))
+
+
+
 MIGRATIONS = [
     (1, _migration_1),
     (2, _migration_2),
@@ -108,6 +118,7 @@ MIGRATIONS = [
     (5, _migration_5),
     (6, _migration_6),
     (7, _migration_7),
+    (8, _migration_8),
 ]