Add file-backed persistence to the internal logWriter so runtime logs
survive service restarts. When internal logging is enabled (CD mode,
no explicit log_path), writes are teed to both the existing in-memory
ring buffer and a rotated file on disk (ctrld.log in the home directory).
File rotation: 5MB max with 1 backup (ctrld.log.1), so max ~10MB on disk.
Log view/send now reads from the persisted files (including backup) to
provide complete history across restarts. Live tail continues to use
the in-memory subscriber mechanism unchanged.
Activation: same conditions as existing internal logging — CD mode only,
no log_path configured. No new config options or dependencies.
For partial init log data (does not end with a newline), the log writer
discard data after the last newline to make the log prettier, then write
the init end marker. This causes the marker could be written more than
once, since the second overflows will preserve the data which does
include the marker from the first write.
To fix this, ensure that the init end marker is only written once, and
the second overflows will preserve data until the marker instead of the
fixed initial size like the first one.
Codescribe