fix(clip): a clip is held to its owner's storage cap, and its limits and failures say the server's truth

- The cut file is measured against what its owner has left, for a YouTube range (whose fetch never
  reads yt-dlp's size ceiling) and for a Plex clip (which fetches nothing), before the fetch and
  again before it is placed; a refusal leaves the asset pending for a Retry.
- A silent Plex file is cut silent; a file the probe cannot read says so.
- A second job on a failed or renamed clip gets the same YouTube diagnosis and the fetched title.
- The "too long" refusal names the server's cap; a contract test holds the client's copies of the
  clip limits to clip.py; the shipped player clients are pinned against the installed yt-dlp.
- One HDR transfer set and one rating_key lookup; job status words from JobStatus; the display-name
  guard sees subscript writes and the clip route; stale comments and types follow the clip job.

backend/tests/test_adapters.py

@@ -175,6 +175,21 @@ def test_the_cookie_capable_clients_match_the_installed_ytdlp():
     assert set(YouTubeAdapter._AUTHED_DEFAULT) <= live
 
 
+def test_the_shipped_player_clients_exist_in_the_installed_ytdlp():
+    # yt-dlp skips a client it does not know with a warning and falls back to its own defaults, so
+    # a bump that renames or drops one (tv_simply, the one measured to deliver HD) would change
+    # what every download is fetched with, silently. Read from the Settings defaults, not from
+    # `settings`, which an environment may override.
+    from yt_dlp.extractor.youtube._base import INNERTUBE_CLIENTS
+
+    from app.config import Settings
+
+    fields = Settings.model_fields
+    for knob in ("download_player_clients", "download_player_clients_fallback"):
+        names = Settings._clients(fields[knob].default)
+        assert names and set(names) <= set(INNERTUBE_CLIENTS), (knob, names)
+
+
 def test_youtube_ydl_opts_extra_carries_player_client_and_pot():
     ea = YouTubeAdapter().ydl_opts_extra(["android_vr"])["extractor_args"]
     assert ea["youtube"]["player_client"] == ["android_vr"]