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.
calendar_feed.py/calendar_render.py: fetch/merge per-user ICS feeds,
render agenda/week/month views. manage_overlay.py: composites the
manage-button overlay server-side (QR, battery, location/date,
share-QR, face labels), reused by every render mode. device.py/common.py
wire both together: mode dispatch for /frame/image+advance+back, and
the &manage=1 flag. Plus UI (frame_config.html Calendar card, settings
calendar URL field) and the icalendar/recurring-ical-events deps.
tfaour