Logging moved to a logs.db SQLite store, but MANUAL.md, MANUAL.html and
SPEC.md still documented info_*.log / error_*.log / structured.json and a
midnight-rollover limitation that no longer exist. Replace those sections with
the logs.db reality: levels (info/error to db+stdout/stderr, debug db-only),
progress-to-stdout-only, retention via log_retention_days, and that recent
events are viewable in the dashboard / GET /status.
Closes#6
Rename the Go module, the cmd/ entrypoint dir, the binary, the default config
dir (~/.config/av1dae/), the Docker image/compose service, and all docs and
the dashboard wordmark. No behavioral change — import paths and identifiers
only.