Plex (R-1045): the controller asks Plex itself whether it is claimed — after the claim and on the household's „Kész”; no template probe (an older controller would refuse the press forever)

Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

CHANGELOG.md

@@ -38,6 +38,9 @@ Not released yet (bake → vouch → floor, `09` §3 decision 247). Design: felh
   removal pass's alone (`TestPlanDriveGates_SkipsSafelyRemovedDrive`, red before the fix); (2) the removal pass read the
   agent's `state`, which stays „attached" for a registered disk that is gone — presence is now a backing device
   (`TestEjectStep_G4` from the two measured records, red-proved).
+- **„Kész" never opens an unclaimed Plex (R-1045)** — the controller asks Plex itself (`/identity` with the JSON Accept
+  header) both after the claim and on the household's press. The live template carries NO probe: a controller before
+  0.313.0 would send no Accept header and refuse the press forever. `TestPlexDonePress_RefusedWhileUnclaimed` (red-proved).
 - **Old Sonarr/Radarr installs repaired by themselves (R-1047)** — only when /media is no longer bound: same-path root
   folder, `moveFiles:false` editor, rescan, old root removed, Radarr's collections too. `TestRepairOldRoot_K7`
   (red-proved: moveFiles=true is caught).