refactor(db)!: finalize pooled WNDB v2 migration

app/api/problem_details.py

@@ -8,6 +8,8 @@ from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse
 from pydantic import BaseModel, Field
 
+from app.native.wndb.core.database import MaterializedViewRefreshAfterCommitError
+
 
 class ProblemDetails(BaseModel):
     """RFC 9457 compatible error response used by the REST contract."""
@@ -53,6 +55,24 @@ def _problem_response(
 
 
 def install_problem_details_handlers(app: FastAPI) -> None:
+    @app.exception_handler(MaterializedViewRefreshAfterCommitError)
+    async def materialized_view_refresh_error_handler(
+        request: Request,
+        exc: MaterializedViewRefreshAfterCommitError,
+    ) -> JSONResponse:
+        response = _problem_response(
+            request,
+            status_code=503,
+            title="Materialized view refresh failed",
+            detail=(
+                f"Project {exc.project!r} changes were committed, but GIS query "
+                "views could not be refreshed. Do not repeat the write blindly."
+            ),
+            code="materialized_view_refresh_failed_after_commit",
+        )
+        response.headers["X-TJWater-Changes-Committed"] = "true"
+        return response
+
     @app.exception_handler(RequestValidationError)
     async def validation_error_handler(
         request: Request,