fix(map): make area analysis scale-aware

docs/CODEX_EXECUTION_LOG.md

@@ -10953,3 +10953,40 @@ Validation:
   themes through acquisition or persisted national data and semantic
   selection metrics;
 - browser verification follows against the deployed commit on port 1202.
+
+## 2026-07-21 - Scale-aware rectangle analysis
+
+Implemented:
+
+- reproduced the reported provider failure with an approximately 11,468 km2
+  cross-region rectangle: twenty high-resolution adapters received one unsafe
+  bbox and returned their governed size limits;
+- added explicit detail, regional and overview selection tiers before any
+  provider acquisition starts;
+- regional selections up to 50 by 50 km now split compatible vector and point
+  sources into at most sixteen 18 km tiles, resolve the authority zone per tile
+  and combine each provider product as one persisted PostGIS result;
+- added a canonical multi-partition vector selection route with project,
+  readiness and source-product consistency guards and source-feature count
+  deduplication;
+- allowed terrain and flood partition analysis to receive an explicit set of
+  freshly acquired Dataset ids, avoiding accidental reuse of overlapping old
+  bounded rasters;
+- kept 5 m raster analysis behind its real pixel budget and 10 m thematic
+  analysis behind its 50 km scale budget;
+- changed overview selections to query only national or already provisioned
+  scale-compatible datasets and explain the scale choice once, instead of
+  presenting one provider error for every unavailable detail source.
+
+Validation:
+
+- backend import/compile and frontend TypeScript passed after the contract
+  change;
+- focused selection-partition, DHMV and VMM tests passed (30 tests);
+- focused frontend scale, tiling and concurrency tests passed (12 tests).
+
+Remaining in this pass:
+
+- run the complete readiness gate, deploy the immutable revision and repeat
+  both the large overview rectangle and a regional partitioned rectangle in
+  the live browser.