Merge branch 'feature/assets-s3-sharing'

Integrate asset metadata/storage support, TypeScript client asset APIs, docs updates, and the Leaflet demo while resolving conflicts with recent challenge IP/login persistence changes on main.

Made-with: Cursor

internal/store/migrations/0002_assets.sql

@@ -0,0 +1,28 @@
+CREATE TABLE IF NOT EXISTS assets (
+  id TEXT PRIMARY KEY,
+  owner_key TEXT NOT NULL,
+  checksum TEXT NOT NULL,
+  ext TEXT NOT NULL,
+  kind TEXT NOT NULL,
+  mime_type TEXT,
+  size_bytes BIGINT NOT NULL DEFAULT 0,
+  object_key TEXT NOT NULL,
+  is_public BOOLEAN NOT NULL DEFAULT TRUE,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  UNIQUE (owner_key, checksum, ext),
+  UNIQUE (owner_key, object_key)
+);
+
+CREATE TABLE IF NOT EXISTS feature_asset_links (
+  feature_id TEXT NOT NULL REFERENCES features(id) ON DELETE CASCADE,
+  asset_id TEXT NOT NULL REFERENCES assets(id) ON DELETE CASCADE,
+  name TEXT,
+  description TEXT,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  PRIMARY KEY (feature_id, asset_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_assets_owner ON assets(owner_key);
+CREATE INDEX IF NOT EXISTS idx_assets_owner_public ON assets(owner_key, is_public);
+CREATE INDEX IF NOT EXISTS idx_feature_asset_links_asset ON feature_asset_links(asset_id);

internal/store/migrations/0003_features_spatial.sql

@@ -0,0 +1,21 @@
+CREATE EXTENSION IF NOT EXISTS postgis;
+
+ALTER TABLE features
+  ADD COLUMN IF NOT EXISTS geom geometry(PointZ, 4326);
+
+UPDATE features
+SET geom = ST_SetSRID(
+  ST_MakePoint(
+    (geometry->'coordinates'->>0)::double precision,
+    (geometry->'coordinates'->>1)::double precision,
+    CASE
+      WHEN jsonb_array_length(geometry->'coordinates') >= 3 THEN (geometry->'coordinates'->>2)::double precision
+      ELSE 0
+    END
+  ),
+  4326
+)
+WHERE geom IS NULL
+  AND geometry ? 'coordinates';
+
+CREATE INDEX IF NOT EXISTS idx_features_geom_gist ON features USING GIST (geom);