feat(renderer): cartographic upgrades — peaks, inland lakes, scope marker, refined colorbar

[jacaudi]

Summary

Iterative session focused on visual quality and geographic anchoring of the rendered radar PNG. The default render is now noticeably more professional and spatially intuitive. Bundles a container-runtime bug fix that was masking missing Cartopy cache layers.

Visual upgrades

• Scope-style radar marker (open ring + center dot) at the antenna location with haloed station label.
• Per-station peak markers — KATX gets Mt Baker, Glacier Peak, Mt Rainier, Mt Olympus drawn as brown triangles via a new _PEAKS_BY_STATION registry in basemap.py. Stations without an entry render no markers (opt-in, no warning).
• Inland lakes layer (ne_10m_lakes_north_america) wired in so Lake Washington, Lake Tahoe, Lake Pontchartrain, etc. render as water. The global ne_10m_lakes shapefile drops every lake smaller than a Great Lake at every resolution.
• North arrow flipped to point up (was inverted in v2.12.0).
• Colorbar beefed up: thicker bar, integer ticks every 20 dBZ, inline "dBZ" label to the right of the bar, thin black outline, positioned just above the bottom border.
• Footer text bumped 8 pt → 12 pt.
• 15 px white margin frames the radar plot cleanly instead of bleeding to the figure edges.
• City labels force-clipped to the axes patch so east-edge labels don't leak past the right boundary.

Default render shape

• Default plot height bumped 1000 → 1100 so southern coverage features (e.g. Mt Rainier at the edge of KATX's view) get breathing room above the bottom border.
• Y-axis projected limit now scales with the axes pixel aspect ratio so a taller figure actually shows more N-S area instead of just adding whitespace.
• Projected xlim/ylim locked explicitly so Cartopy's default adjustable="box" doesn't introduce uneven internal padding (previously sides=14 px while top/bottom=26 px).

Refactor: single source of truth for defaults

• DEFAULT_RANGE_KM, DEFAULT_WIDTH, DEFAULT_HEIGHT consolidated as module-level constants in render.py and consumed by service.RenderRequest and the FastAPI Query defaults. The three layers can no longer drift.
• Prior drift had the API silently using range_km=230 while the dataclass advertised 150 — found and fixed mid-session.
• Existing test test_render_options_defaults_match_route_defaults updated to assert against the constants directly.

Container fix bundled

The prewarmed Cartopy cache in scripts/cartopy_cache.py was missing admin_2_counties_lakes, roads, LAND (10m), and (now) lakes_north_america. Without them the unprivileged container uid hit PermissionError trying to download missing layers at request time. The script's docstring already required this list be kept in sync with render.py — it had drifted. Build now reports all layers warmed.

Test plan

• uv run pytest tests/ — 67 passed
• Container build succeeds: docker build -t dras-renderer:local .
• Container renders KATX without PermissionError (was 500ing before the cartopy_cache fix)
• Visual review of /render/KATX output — peaks visible, Lake Washington rendering as water, equal margins, colorbar legible
• Deploy to Talos selfhosted ns and confirm in-cluster render matches local

🤖 Generated with Claude Code

[wall-e-one]

🎉 This PR is included in version 2.13.0 🎉

The release is available on:

• v2.13.0
• GitHub release

Your semantic-release bot 📦🚀