[AZ-503] Tile identity → UUIDv5 + integer UPSERT (foundation)

Foundation half of original AZ-503 (split during /autodev step 10 batch 2
on user choice; deferred work moved to AZ-505 with a Blocks link).

Adds deterministic tile identity (UUIDv5 over (z, x, y, source, flight_id))
shared cross-repo with gps-denied-onboard via the pinned TileNamespace
5b8d0c2e-7f1a-4d3b-9c5e-1f3a8e7d2b6c, switches the tiles UPSERT key from
floats to integers with per-flight separation, plumbs FlightId through
UavTileMetadata + handler, and writes UAV evidence to per-flight
on-disk directories so two flights at the same (z, x, y) coexist.

- Common: pure-C# RFC 9562 Uuidv5 (no third-party dep) + FlightId DTO
  field; 10 Python-reference unit vectors verify byte parity.
- DataAccess: migration 014 adds flight_id (uuid NULL), location_hash
  (uuid NOT NULL, backfilled via session-scoped pg_temp.uuidv5),
  content_sha256 (bytea NULL), legacy_id (uuid NULL = preserves
  pre-AZ-503 random id one cycle); drops idx_tiles_unique_location_source
  (AZ-484) and adds idx_tiles_unique_identity keyed on
  (tile_zoom, tile_x, tile_y, tile_size_meters, source,
   COALESCE(flight_id, '00000000-...'::uuid)) + idx_tiles_location_hash.
- TileRepository: ColumnList + UPSERT updated; id never updated on
  conflict (preserves AC-2 idempotence). UpdateAsync extended.
- Services: TileService and UavTileUploadHandler compute deterministic
  Id + LocationHash + ContentSha256 before insert; UAV file path
  becomes ./tiles/uav/{flight_id or 'none'}/{z}/{x}/{y}.jpg.
- Tests: Uuidv5Tests (10 reference vectors), UavTileFilePathTests
  (per-flight + anonymous paths), UavTileUploadHandlerTests (AC-2,
  AC-3, AC-7, AC-11 unit-level), UavUploadTests (AC-3 + AC-4
  integration: multi-flight DB coexistence with shared location_hash
  + distinct file_path; float-different lat/lon collapse to 1 row),
  MigrationTests (column shape, idx_tiles_unique_identity supersedes
  AZ-484 index, deterministic backfill).
- IntegrationTests project references Common to reuse Uuidv5 in raw
  SQL seeds.
- AZ-488 MultiSourceCoexistence seed fixed to populate location_hash
  (otherwise migration 014's NOT NULL constraint fails).

ACs covered: AC-1, AC-2, AC-3, AC-4, AC-7, AC-8, AC-11.
ACs deferred to AZ-505: AC-5, AC-6, AC-9, AC-10, AC-12.

Co-authored-by: Cursor <cursoragent@cursor.com>

SatelliteProvider.Services.TileDownloader/TileService.cs

@@ -1,3 +1,5 @@
+using System.Globalization;
+using System.Security.Cryptography;
 using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
@@ -144,9 +146,33 @@ public class TileService : ITileService
     private TileEntity BuildTileEntity(DownloadedTileInfoV2 downloaded)
     {
         var now = DateTime.UtcNow;
+        var source = TileSourceConverter.ToWireValue(TileSource.GoogleMaps);
+        // AZ-503: deterministic UUIDv5 over (z, x, y, source, flight_id-or-zero).
+        // google_maps tiles have no flight_id so the name fragment uses the
+        // canonical all-zeros UUID; the same Python-side serialization in
+        // gps-denied-onboard produces byte-identical IDs.
+        var idName = string.Create(CultureInfo.InvariantCulture,
+            $"{downloaded.ZoomLevel}/{downloaded.X}/{downloaded.Y}/{source}/{Guid.Empty}");
+        var locationHashName = string.Create(CultureInfo.InvariantCulture,
+            $"{downloaded.ZoomLevel}/{downloaded.X}/{downloaded.Y}");
+        var id = Uuidv5.Create(Uuidv5.TileNamespace, idName);
+        var locationHash = Uuidv5.Create(Uuidv5.TileNamespace, locationHashName);
+        // content_sha256 is computed from the actual JPEG body on disk. Google Maps
+        // downloads land on disk before this method runs (FilePath is set by the
+        // downloader), so a single read here is safe and avoids re-streaming. If
+        // the file is missing for any reason, leave ContentSha256 null and rely on
+        // the application invariant of "NOT NULL for AZ-503+ inserts" surfacing
+        // the problem in tests rather than silently inserting a sentinel digest.
+        byte[]? contentSha256 = null;
+        if (File.Exists(downloaded.FilePath))
+        {
+            using var stream = File.OpenRead(downloaded.FilePath);
+            contentSha256 = SHA256.HashData(stream);
+        }
+
         return new TileEntity
         {
-            Id = Guid.NewGuid(),
+            Id = id,
             TileZoom = downloaded.ZoomLevel,
             TileX = downloaded.X,
             TileY = downloaded.Y,
@@ -158,10 +184,14 @@ public class TileService : ITileService
             MapsVersion = null,
             Version = null,
             FilePath = downloaded.FilePath,
-            Source = TileSourceConverter.ToWireValue(TileSource.GoogleMaps),
+            Source = source,
             CapturedAt = now,
             CreatedAt = now,
-            UpdatedAt = now
+            UpdatedAt = now,
+            FlightId = null,
+            LocationHash = locationHash,
+            ContentSha256 = contentSha256,
+            LegacyId = null
         };
     }