Implement canonical MapLibre style pipeline across protocols

[mikemcdougall]

Background

MVP docs call for MapLibre Style Spec v8 as the canonical layer style, edited via embedded Maputnik, and converted to GeoServices drawingInfo for FeatureServer responses (see docs/ARCHITECTURE.md Styling section and docs/adr/0002-maplibre-canonical-style.md). Current style endpoints are placeholders and do not persist or translate styles.

Scope

Implement the canonical MapLibre style pipeline so a single style edited in Maputnik drives FeatureServer and OGC metadata outputs.

Acceptance Criteria

• DB: layers has maplibre_style JSONB (canonical), geoservices_drawing_info JSONB (cache/import), and style_version INT (migration added if missing).
• Admin metadata style endpoints:
  • GET /api/v1/admin/metadata/layers/{layerId}/style returns stored MapLibre style and GeoServices drawingInfo (converted if cache empty).
  • PUT validates MapLibre v8, saves maplibre_style, increments style_version, clears cached geoservices_drawing_info, and returns updated style payload.
  • If request includes only drawingInfo, server converts to MapLibre and stores MapLibre as canonical (import/compat path).
• FeatureServer layer metadata includes drawingInfo derived from MapLibre when cache is empty, then cached for future requests.
• OGC API Features collection metadata exposes a style link to the public MapLibre style endpoint (see TileJSON metadata endpoint #20).
• Converters:
  • Support Simple/UniqueValue/ClassBreaks renderers (MapLibre <-> GeoServices).
  • Unsupported renderer types fall back to a sensible default and emit a warning log.
• Cache invalidation on style update (layer metadata + output cache tags).
• Tests cover: style save/load, conversion for each renderer type, and FeatureServer metadata includes drawingInfo.

Dependencies

• Public style endpoints and TileJSON style link are tracked in TileJSON metadata endpoint #20.

Out of Scope

• OGC API Styles CRUD endpoints (planned post-MVP)
• Advanced GeoServices renderers (heatmap, dot density, picture symbols, temporal)