fix(node,hub): HEVC transcode fallback, live-add progress, per-group TMDB toggle

Three bugs found live testing the Videos app against a real HEVC/EAC3 show,
plus a design change requested afterward:

- Streaming always did "-c:v copy", which faithfully reports a source's real
  hev1 codec string but is unplayable in a browser with no HEVC decoder
  (most Chrome/Linux builds). The node now transcodes to H264 whenever the
  probed codec is browser-incompatible (media_probe.py's new
  BROWSER_INCOMPATIBLE_VIDEO_CODECS), with a `transcode_incompatible_video`
  node.toml opt-out for operators who know their viewers already decode it.

- Dropping a whole season into an already-watched folder gave no scanning
  indicator and no progress bar: IndexProgress was only ever updated by the
  two bulk scan paths, never by the real-time per-file watchdog path
  (_schedule_update/_debounce/_update_entry). That path now accounts a
  "burst" the same way, without double-counting a file rewritten mid-debounce.

- A stray literal "0" rendered in the video detail modal when there was no
  TMDB match (`meta.confidence` is 0, and `0 && x` renders "0" in JSX/htm,
  not nothing) — `confident` is now a real boolean.

- Whether TMDB is used at all moves from a node-wide setting to per-group
  (OP_TMDB_ENABLED/tmdb_enabled/tmdb_enabled_ack, scoped like OP_VIDEO_ROOT):
  an operator running a real media-library group alongside test/demo groups
  on one node wants outbound TMDB traffic for the one that needs it, not all
  of them. The custom API token and query language stay node-wide, one
  shared credential/cache (tmdb_config/OP_TMDB_CONFIG, unchanged reasoning).
  MNP_VERSION 0.6 -> 0.7, additive.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LAmyXtc6dAADsH23ydXQpY

1 files changed, 14 insertions, 7 deletions

diff --git a/packages/meshbay-common/src/meshbay_common/adminop.py b/packages/meshbay-common/src/meshbay_common/adminop.py
index 51396c7..df806a9 100644
--- a/packages/meshbay-common/src/meshbay_common/adminop.py
+++ b/packages/meshbay-common/src/meshbay_common/adminop.py
@@ -61,15 +61,22 @@ OP_APPS_ENABLED = "apps_enabled"
 # security property in itself, but the pattern (every operator setting is
 # signed) is what keeps the authorization model simple to reason about.
 OP_SET_SCAN_SETTINGS = "set_scan_settings"
-# Whether the node calls TMDB at all, and whether it uses the operator's own
-# API token instead of the shipped default. Signed like the rest: it turns
-# on outbound third-party network traffic that did not exist before the
-# Videos app (docs/mediacenter.md §5.5, §8) — an unsigned toggle would let
-# any member turn on egress the operator never agreed to.
+# Whether the node uses the operator's own API token/language instead of the
+# shipped default — node-wide (docs/mediacenter.md §5.5), one credential
+# shared by every group. Signed like the rest: it turns on outbound
+# third-party network traffic that did not exist before the Videos app
+# (§8) — an unsigned change would let any member alter egress the operator
+# never agreed to.
 OP_TMDB_CONFIG = "tmdb_config"
+# Whether the node calls TMDB *at all* for this group — per-group, unlike
+# tmdb_config above: a real media-library group and a test/demo group on the
+# same node need not share the decision to spend TMDB quota and make
+# outbound requests. Signed for the same reason as tmdb_config.
+OP_TMDB_ENABLED = "tmdb_enabled"
 # Which folder (possibly a subfolder of a shared root) is the Videos app's
-# entry point for this group — per-group, unlike tmdb_config. Signed like
-# the rest: it decides what every member's Videos tab shows.
+# entry point for this group — per-group, like tmdb_enabled above and
+# unlike tmdb_config's token/language. Signed like the rest: it decides what
+# every member's Videos tab shows.
 OP_VIDEO_ROOT = "video_root"
 # Correcting a wrong automatic TMDB match — signed for the same reason as
 # tmdb_config: it changes what every member sees for a show/movie, node-wide