[AZ-305] c6 PostgresFilesystemStore: TileStore + TileMetadataStore impl

Adds the production PostgresFilesystemStore implementing both protocols
in a single class. Filesystem-backed JPEG I/O (atomic sidecar write,
read-only mmap) + Postgres-backed metadata (spatial bbox, LRU, voting,
upload bookkeeping). Wires composition via `from_config` classmethod.

Key behaviors:
- AC-3 strict reading: INSERT runs first inside an open transaction;
  duplicate-key collisions raise `TileMetadataError` BEFORE any byte is
  written, leaving the original file + sidecar byte-identical. Atomic
  sidecar write happens inside the same transaction; commit closes it.
  Comp-delete remains as a safety net for the rare commit-after-write
  failure path.
- AC-2 content-hash gate runs before any I/O.
- Construction performs an orphan-file reconciliation scan and emits an
  INFO `c6.store.construct` log with steady-state stats.

Adds `c6.write` and `c6.write_failed` FDR record kinds (schema v1.1.0,
forward-compatible) and a thin operator CLI at
`c6_tile_cache.tools dump` for inspection.

Dependencies: adds `psycopg-pool>=3.2,<4.0` for the connection pool used
on the F3 read-hot path.

Tests: 25 new tests for c6_tile_cache cover AC-1..AC-15 plus
MmapTilePixelHandle + helper round-trips. Full Tier-2 unit suite passes
(1215 passed, 8 skipped, 1 pre-existing unrelated failure
`test_ac8_read_host_tuple_on_jetson` — missing `pynvml` on macOS,
Jetson-only).

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

src/gps_denied_onboard/runtime_root/storage_factory.py

@@ -52,7 +52,7 @@ def _is_build_flag_on(flag_name: str) -> bool:
     return raw.strip().lower() in {"on", "1", "true", "yes"}
 
 
-def _c6_config(config: "Config") -> "C6TileCacheConfig":
+def _c6_config(config: Config) -> C6TileCacheConfig:
     """Pull the registered C6 config block.
 
     ``c6_tile_cache.__init__`` registers it on import; if the package
@@ -62,18 +62,21 @@ def _c6_config(config: "Config") -> "C6TileCacheConfig":
     return config.components["c6_tile_cache"]
 
 
-def build_tile_store(config: "Config") -> "TileStore":
+def build_tile_store(config: Config) -> TileStore:
     """Construct the :class:`TileStore` impl selected by config.
 
     Today only ``"postgres_filesystem"`` is wired; the runtime label
     is validated at config-load time so unknown labels never reach
-    here. Concrete impl is produced by AZ-305.
+    here. Concrete impl produced by AZ-305 — the constructor is
+    invoked via ``PostgresFilesystemStore.from_config(config)`` which
+    wires the ``ConnectionPool`` / ``FdrClient`` / logger / static
+    helper dependencies from the config block.
     """
     block = _c6_config(config)
     runtime = block.store_runtime
     if runtime == "postgres_filesystem":
         try:
-            from gps_denied_onboard.components.c6_tile_cache.postgres_filesystem_store import (  # noqa: PLC0415
+            from gps_denied_onboard.components.c6_tile_cache.postgres_filesystem_store import (
                 PostgresFilesystemStore,
             )
         except ModuleNotFoundError as exc:
@@ -83,13 +86,13 @@ def build_tile_store(config: "Config") -> "TileStore":
                 "'c6_tile_cache.postgres_filesystem_store' has not been "
                 "built into this binary yet (AZ-305 pending)."
             ) from exc
-        return PostgresFilesystemStore(config)
+        return PostgresFilesystemStore.from_config(config)
     raise RuntimeNotAvailableError(
         f"TileStore runtime {runtime!r} is not buildable in this binary."
     )
 
 
-def build_tile_metadata_store(config: "Config") -> "TileMetadataStore":
+def build_tile_metadata_store(config: Config) -> TileMetadataStore:
     """Construct the :class:`TileMetadataStore` impl selected by config.
 
     Today the same ``PostgresFilesystemStore`` class implements both
@@ -102,7 +105,7 @@ def build_tile_metadata_store(config: "Config") -> "TileMetadataStore":
     runtime = block.metadata_runtime
     if runtime == "postgres_filesystem":
         try:
-            from gps_denied_onboard.components.c6_tile_cache.postgres_filesystem_store import (  # noqa: PLC0415
+            from gps_denied_onboard.components.c6_tile_cache.postgres_filesystem_store import (
                 PostgresFilesystemStore,
             )
         except ModuleNotFoundError as exc:
@@ -112,13 +115,13 @@ def build_tile_metadata_store(config: "Config") -> "TileMetadataStore":
                 "'c6_tile_cache.postgres_filesystem_store' has not been "
                 "built into this binary yet (AZ-305 pending)."
             ) from exc
-        return PostgresFilesystemStore(config)
+        return PostgresFilesystemStore.from_config(config)
     raise RuntimeNotAvailableError(
         f"TileMetadataStore runtime {runtime!r} is not buildable in this binary."
     )
 
 
-def build_descriptor_index(config: "Config") -> "DescriptorIndex":
+def build_descriptor_index(config: Config) -> DescriptorIndex:
     """Construct the :class:`DescriptorIndex` impl selected by config.
 
     Gated by ``BUILD_FAISS_INDEX``: if the flag is OFF, the concrete
@@ -134,7 +137,7 @@ def build_descriptor_index(config: "Config") -> "DescriptorIndex":
                 "BUILD_FAISS_INDEX=ON in this binary; the flag is OFF."
             )
         try:
-            from gps_denied_onboard.components.c6_tile_cache.faiss_descriptor_index import (  # noqa: PLC0415
+            from gps_denied_onboard.components.c6_tile_cache.faiss_descriptor_index import (
                 FaissDescriptorIndex,
             )
         except ModuleNotFoundError as exc: