Adds a record_enabled field to streams (migration 017, default false).
Streams no longer record by default; recording must be opted into when
creating or editing a stream.
- mediamtx path API: when recording is disabled, adds a per-key path
override (record:false) so mediamtx never writes the file to disk.
Override is cleared on key regeneration and re-applied to the new key.
- stream-end hook: skips recording processing and immediately marks stream
offline when record_enabled is false.
- stream-live hook: only stores early-start trim offset when recording is
enabled; returns record_enabled in the JSON response.
- on-ready-hw.sh: reads record_enabled from the stream-live response and
skips FFmpeg entirely when recording is disabled.
- ChannelPage: adds a "Save recording" checkbox to the New Stream modal
and all inline edit forms.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>