Triage high-value ty diagnostics

Apply the highest-value typing fixes from the ty baseline pass:
- align migration row typing with SQLAlchemy RowMapping sequences
- accept refreshable callback return type in homepage gallery
- guard nullable media URL before ui.image in people photos
- guard nullable source MIME type before startswith checks
- fix tests/test_db collect() return annotation to match 4-tuple

This clears all actionable ty findings from that set and leaves only
known SQLModel/SQLAlchemy descriptor false positives.

Co-authored-by: Copilot App <[email protected]>

src/transcription/db/migration.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import base64
 import json
 import shutil
+from collections.abc import Sequence
 from dataclasses import dataclass
 from datetime import UTC
 from datetime import date
@@ -18,6 +19,7 @@ from sqlalchemy import Table
 from sqlalchemy import create_engine
 from sqlalchemy import inspect as sqlalchemy_inspect
 from sqlalchemy import select
+from sqlalchemy.engine import RowMapping
 from sqlalchemy.engine import make_url
 from sqlmodel import SQLModel
 
@@ -69,7 +71,7 @@ def export_bundle(*, source_db_url: str, source_upload_dir: Path, bundle_dir: Pa
     }
 
     engine = create_engine(source_db_url)
-    legacy_portrait_rows: list[dict[str, Any]] = []
+    legacy_portrait_rows: Sequence[RowMapping] = ()
     try:  # noqa: PLR1702
         inspector = sqlalchemy_inspect(engine)
         source_tables = set(inspector.get_table_names())
@@ -195,9 +197,10 @@ def default_sync_db_url(settings: Settings | None = None) -> str:
     return get_database_url(runtime_settings).replace("+aiosqlite", "").replace("+asyncpg", "").replace("+psycopg", "")
 
 
-def _serialize_row(row: dict[str, Any], *, table_name: str, source_upload_dir: Path) -> dict[str, Any]:
+def _serialize_row(row: RowMapping, *, table_name: str, source_upload_dir: Path) -> dict[str, Any]:
     serialized: dict[str, Any] = {}
-    for key, value in row.items():
+    for raw_key, value in row.items():
+        key = str(raw_key)
         serialized_value = _serialize_value(value)
         if table_name == "source" and key == "file_path" and isinstance(serialized_value, str):
             serialized[key] = _canonical_media_relative_path(
@@ -315,7 +318,7 @@ def _prepare_photo_payload_and_uploads(  # noqa: PLR0915
     *,
     payload: dict[str, Any],
     uploads_bundle_dir: Path,
-    legacy_portrait_rows: list[dict[str, Any]],
+    legacy_portrait_rows: Sequence[RowMapping],
 ) -> None:
     photo_rows = payload.setdefault("tables", {}).setdefault("photo", [])
     photos_dir = uploads_bundle_dir / "photos"

src/transcription/ui/pages/home_page.py

@@ -43,7 +43,7 @@ def _render_homepage_gallery(
     base_url: str,
     enable_rotation: bool = False,
     rotate_enabled: list[bool] | None = None,
-    on_change: Callable[[], None] | None = None,
+    on_change: Callable[[], object] | None = None,
 ) -> None:
     if not photos:
         render_empty_state("No homepage image uploaded yet.")

src/transcription/ui/pages/people_page.py

@@ -283,7 +283,10 @@ def register_page() -> None:  # noqa: PLR0915
                                 base_url=str(request.base_url),
                             )
                             with ui.element("div").classes("relative w-full"):
-                                ui.image(photo_url).classes("w-full rounded-md")
+                                if photo_url is None:
+                                    ui.label("Image unavailable").classes("w-full text-sm ui-text-muted p-2")
+                                else:
+                                    ui.image(photo_url).classes("w-full rounded-md")
                                 description_text = photo.description or "No description"
                                 ui.label(description_text).classes(
                                     "absolute inset-x-0 bottom-0 text-center text-white text-xs font-semibold "

src/transcription/ui/pages/sources_page.py

@@ -407,7 +407,7 @@ def _render_source_metadata_column(
 
 def _resolve_source_detail_layout(*, source: Source, settings: Settings) -> str:
     media_type = lookup_source_mime_type(source.file_path)
-    if not media_type.startswith("image/"):
+    if media_type is None or not media_type.startswith("image/"):
         return "standard"
     absolute = (settings.upload_dir / Path(source.file_path)).resolve()
     dimensions = _read_image_dimensions(absolute)