[AZ-505] Tile inventory endpoint + HTTP/2 + Leaflet covering index

Production code:
- POST /api/satellite/tiles/inventory (XOR body, 5000-cap,
  most-recent-per-location_hash select, present/absent shaping).
- Kestrel HttpProtocols.Http1AndHttp2 on every listener (AC-5).
- Migration 015 creates tiles_leaflet_path covering index over
  (location_hash, captured_at DESC, updated_at DESC, id DESC)
  INCLUDE (file_path, source); drops superseded idx_tiles_location_hash.
- TileRepository.GetByTileCoordinatesAsync rewired to filter by
  location_hash (Index Only Scan via tiles_leaflet_path).
- TileRepository.GetTilesByLocationHashesAsync added with Npgsql-
  direct ANY($1::uuid[]) binding (Dapper IEnumerable expansion is
  incompatible with the array form).
- Uuidv5.LocationHashForTile centralises the UUIDv5(TileNamespace,
  "{z}/{x}/{y}") formula — single source of truth for the cross-repo
  invariant (gps-denied-onboard parity).

Contracts:
- New: contracts/api/tile-inventory.md v1.0.0.
- Bumped: contracts/data-access/tile-storage.md to v2.0.0 (joint
  ownership by AZ-503-foundation + AZ-505: schema + covering index +
  GetByTileCoordinatesAsync rewrite).

Tests:
- TileInventoryTests covers AC-1, AC-2 (DB-level), AC-4, AC-6.
- Http2MultiplexingTests covers AC-5 (20 concurrent multiplexed GETs
  over h2c via SocketsHttpHandler + AppContext Http2Unencrypted switch).
- LeafletPathIndexOnlyTests covers AC-3 (EXPLAIN (ANALYZE, BUFFERS)
  asserts Index Only Scan over tiles_leaflet_path with heap_blocks=0).

Docs:
- architecture.md, system-flows.md, data_model.md, module-layout.md,
  glossary.md, modules/api_program.md, modules/dataaccess_tile_repository.md,
  components/02_data_access/description.md all updated to reference the
  v2.0.0 tile-storage contract + new tile-inventory contract + AC-7.

Reports:
- batch_01_cycle6_report.md, batch_01_cycle6_review.md,
  implementation_completeness_cycle6_report.md (PASS),
  implementation_report_tile_inventory_cycle6.md.

Task spec moved todo/ -> done/.

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

SatelliteProvider.Api/Program.cs

@@ -39,6 +39,17 @@ var uavBatchBodyLimit = checked((long)uavQuality.MaxBatchSize * uavQuality.MaxBy
 builder.Services.Configure<KestrelServerOptions>(options =>
 {
     options.Limits.MaxRequestBodySize = uavBatchBodyLimit;
+    // AZ-505: enable HTTP/2 alongside HTTP/1.1 on every Kestrel endpoint so
+    // programmatic clients (httpx http2=True, .NET HttpClient with
+    // HttpVersionPolicy.RequestVersionExact) can multiplex tile reads on a
+    // single TCP connection. Browsers cannot use h2c (HTTP/2 cleartext)
+    // without ALPN+TLS, so they continue on HTTP/1.1 — the win for browsers
+    // is the AZ-505 covering-index hot path, not multiplexing. HTTP/3/QUIC
+    // is intentionally out of scope (see AZ-505 task spec § Excluded).
+    options.ConfigureEndpointDefaults(listen =>
+    {
+        listen.Protocols = HttpProtocols.Http1AndHttp2;
+    });
 });
 builder.Services.Configure<FormOptions>(options =>
 {
@@ -184,6 +195,17 @@ app.MapGet("/api/satellite/tiles/mgrs", GetSatelliteTilesByMgrs)
     .ProducesProblem(StatusCodes.Status501NotImplemented)
     .WithOpenApi(op => new(op) { Summary = "Get satellite tiles by MGRS coordinates (NOT IMPLEMENTED)" });
 
+app.MapPost("/api/satellite/tiles/inventory", GetTilesInventory)
+    .RequireAuthorization()
+    .Accepts<TileInventoryRequest>("application/json")
+    .Produces<TileInventoryResponse>(StatusCodes.Status200OK)
+    .ProducesProblem(StatusCodes.Status400BadRequest)
+    .WithOpenApi(op => new(op)
+    {
+        Summary = "Bulk tile inventory lookup by (z,x,y) coords or location_hash",
+        Description = "AZ-505 / `tile-inventory.md` v1.0.0. Body MUST populate exactly one of `tiles` (array of `{tileZoom,tileX,tileY}`) OR `locationHashes` (array of UUIDv5). Response order matches request order. Returns one entry per request item with `present: true|false`; when present, identity + recency fields are included. Hard cap: 5000 entries per call (HTTP 400 above)."
+    });
+
 app.MapPost("/api/satellite/upload", UploadUavTileBatch)
     .RequireAuthorization(SatellitePermissions.UavUploadPolicy)
     .Accepts<UavTileBatchUploadRequest>("multipart/form-data")
@@ -260,6 +282,42 @@ IResult GetSatelliteTilesByMgrs(string mgrs, double squareSideMeters)
         detail: "MGRS-based tile retrieval is not implemented.");
 }
 
+async Task<IResult> GetTilesInventory(
+    [FromBody] TileInventoryRequest? request,
+    HttpContext httpContext,
+    ITileService tileService)
+{
+    if (request is null)
+    {
+        return Results.Problem(
+            statusCode: StatusCodes.Status400BadRequest,
+            title: "Invalid tile inventory request",
+            detail: "Request body is required.");
+    }
+
+    var tileCount = request.Tiles?.Count ?? 0;
+    var hashCount = request.LocationHashes?.Count ?? 0;
+    if ((tileCount == 0) == (hashCount == 0))
+    {
+        return Results.Problem(
+            statusCode: StatusCodes.Status400BadRequest,
+            title: "Invalid tile inventory request",
+            detail: "Populate exactly one of `tiles` or `locationHashes`. Sending both, or neither, is not allowed.");
+    }
+
+    var totalCount = Math.Max(tileCount, hashCount);
+    if (totalCount > TileInventoryLimits.MaxEntriesPerRequest)
+    {
+        return Results.Problem(
+            statusCode: StatusCodes.Status400BadRequest,
+            title: "Invalid tile inventory request",
+            detail: $"Inventory request capped at {TileInventoryLimits.MaxEntriesPerRequest} entries; got {totalCount}.");
+    }
+
+    var response = await tileService.GetInventoryAsync(request, httpContext.RequestAborted);
+    return Results.Ok(response);
+}
+
 async Task<IResult> UploadUavTileBatch(
     HttpContext httpContext,
     IUavTileUploadHandler handler,