fix(capture): every process registers every table before its first query

The models now live in their units' packages, and a core model names a unit's by
string (User.subscriptions -> Subscription). The download child imports neither
catalog nor app.tables before db.get, so mapper configuration failed and every
download, clip, edit and upload job died with child_exit. Each entry point now
imports app.tables, and a test imports each one in a clean interpreter.

backend/app/downloads/runner.py

@@ -16,6 +16,7 @@ import shutil
 import subprocess
 import sys
 
+import app.tables  # noqa: F401 — a fresh interpreter: every table, before the first query
 from app import logs
 from app import logsink
 from app.config import settings

backend/app/main.py

@@ -28,6 +28,7 @@ log = logs.get_logger(__name__)
 from app import bodylimit, collation, logsink, state, sysconfig  # noqa: E402 — logging is configured first
 from app.config import settings  # noqa: E402 — logging is configured first
 from app.db import SessionLocal, engine  # noqa: E402 — logging is configured first
+import app.tables  # noqa: E402 — every table, before the first query
 from app.downloads import service as download_service  # noqa: E402 — logging is configured first
 from app.downloads import storage  # noqa: E402 — logging is configured first
 from app.plex import stream as plex_stream  # noqa: E402 — logging is configured first

backend/app/worker.py

@@ -31,6 +31,7 @@ from functools import partial
 from sqlalchemy import text
 from sqlalchemy.orm import Session
 
+import app.tables  # noqa: F401 — every table, before the first query
 from app import logs
 from app import logsink
 from app import sysconfig

backend/tests/test_entry_points.py

@@ -0,0 +1,63 @@
+"""Every process the app runs as sees every table before its first query.
+
+The units declare their tables in their own `models` modules, and a core model names a unit's by
+string (`User.subscriptions` → `Subscription`). A fresh interpreter that never imported the unit's
+module fails to configure its mappers on its first query: the download child once did exactly that,
+and every job failed, while this suite stayed green — it imports `app.tables` in-process, which hides
+the gap. So each entry point is imported here in a clean interpreter, and must register the whole
+schema on its own.
+"""
+
+import ast
+import subprocess
+import sys
+from pathlib import Path
+
+import app.tables  # noqa: F401
+from app.db import Base
+
+BACKEND = Path(__file__).parent.parent
+APP = BACKEND / "app"
+
+# Each `python -m` module the deployment starts, and the API's app module.
+ENTRY_POINTS = ("app.main", "app.worker", "app.downloads.runner")
+
+_PROBE = (
+    "import importlib, sys\n"
+    "importlib.import_module(sys.argv[1])\n"
+    "from sqlalchemy.orm import configure_mappers\n"
+    "from app.db import Base\n"
+    "configure_mappers()\n"
+    "print('\\n'.join(sorted(Base.metadata.tables)))\n"
+)
+
+
+def test_each_entry_point_registers_the_whole_schema_on_its_own():
+    whole = sorted(Base.metadata.tables)
+    for module in ENTRY_POINTS:
+        r = subprocess.run(
+            [sys.executable, "-c", _PROBE, module],
+            cwd=BACKEND,
+            capture_output=True,
+            text=True,
+            timeout=120,
+            check=False,
+        )
+        assert r.returncode == 0, (module, r.stderr[-2000:])
+        assert r.stdout.split() == whole, module
+
+
+def test_every_module_that_runs_as_a_process_is_listed():
+    mains = set()
+    for path in APP.rglob("*.py"):
+        tree = ast.parse(path.read_text(encoding="utf-8"))
+        for node in tree.body:
+            if (
+                isinstance(node, ast.If)
+                and isinstance(node.test, ast.Compare)
+                and isinstance(node.test.left, ast.Name)
+                and node.test.left.id == "__name__"
+            ):
+                rel = path.relative_to(BACKEND).with_suffix("").as_posix()
+                mains.add(rel.replace("/", "."))
+    assert mains <= set(ENTRY_POINTS), mains - set(ENTRY_POINTS)