The shipped config could not load on a machine without a .env

config/default.yaml reads its camera's host, username and password from
${ENV}. Unset placeholders parse as YAML null, and CameraConfig had no
_normalize_blanks - the guard ApiSection and EmailSection have had all
along - so loading it raised three pydantic errors and the engine would
not start at all. On a developer's checkout .env is right there, which is
why this survived: the failing machine is every machine the product is
actually installed on, and installer/build.ps1 runs this suite, so the
Windows build would have failed on a fresh clone.

The normalisation is field-by-field, never a blanket None -> "": `webcam`
is an Optional[int] whose None means "this is not a webcam", and `tuning`
is a nested model. Sweeping either trades one validation error for
another - which it did, on the first attempt.

Second bug behind the same line: that camera entry would then have been
SEEDED into a fresh install, giving a shop a camera called cam1 that
nobody added, retrying a connection to "" forever, with the first task on
a new PC being to work out what it was. CameraConfig.addressed() says
what a camera entry needs to be one, and seed() drops the rest.

Found by cloning the repository into a temp directory and running the
tests there. Nothing in a working tree can find this class of bug.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HViLj9gYNRtSr7YVZmW5sn

behavision/cameras.py

@@ -182,13 +182,22 @@ class CameraStore:
 
         After that the store is authoritative — otherwise a camera the user
         deleted in the UI would reappear on every restart.
+
+        Entries with no address are dropped rather than imported. The bundled
+        config declares one whose host comes from the environment, which is
+        right for a checkout with a .env and resolves to nothing on every
+        machine the product is actually installed on. Seeding that would put a
+        camera the shop never added into a brand new install, permanently
+        failing to connect to "" — and the first thing they would have to do is
+        work out what it was and delete it.
         """
         with self._lock:
-            if self.path.exists() or not cameras:
+            usable = [c for c in cameras if c.addressed()]
+            if self.path.exists() or not usable:
                 return False
-            for cam in cameras:
+            for cam in usable:
                 self._cameras[cam.id] = cam
             self._save()
             log.info("seeded %d camera(s) from YAML into %s",
-                     len(cameras), self.path)
+                     len(usable), self.path)
             return True