Post-M2 self-walkthrough polish, batched into one commit.
Map / heat:
- fix heat-layer white-screen crash after login (add layer to map before
setLatLngs; an off-map leaflet.heat layer has a null _map and throws)
- normalize each heat layer to the densest pixel cell visible in the CURRENT
viewport (maxZoom:0 so intensity factor f=1) and recompute on moveend/zoomend,
so sparse poo data reaches red and stays normalized at any zoom level
- dark CARTO basemap tiles when the color scheme is dark
UI:
- dark-mode toggle in the top-right, beside the settings gear
- switch top-right nav (records / theme / settings / logout) to Feather icons
with hover tooltips
- home: Grafana-style quick time-range presets + back/forward shift buttons,
placed between the From/To pickers and Apply; fix Select/tooltip z-index
(Leaflet stacking) and the shift-button height alignment
API client:
- stop flooding GET /api/session with 401s: the session probe and the login
endpoint own their 401s (no global redirect), which fixes the logout hang and
the spinning login page
Compose:
- rename docker-compose.override.yml -> docker-compose.dev.yml as an explicit,
non-auto-layered dev stack (8001, -dev container names, prod-copy ./data DB);
update tests/test_deployment.py (read dev.yml, tolerate the !override tag) and
the README "Docker Compose" section
Tests:
- pixel-grid peak counter, time-range presets, heat-layer ordering regression,
and 401-redirect regression
tliu93