Offline maintenance scripts for OC Chat.
Purpose
-------
Standalone scripts invoked as ``python -m oc_chat.scripts.<name>``.
Not imported at runtime; no startup cost.
Responsibilities
----------------
- Session migration utilities
- Data repair tools
Diagnostics
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Domain: OC_CHAT.MAIN
Levels:
L2 — script lifecycle events
L3 — per-record / per-file semantic details
L4 — deep tracing
Contracts
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- Scripts are idempotent when possible
- Scripts default to --dry-run to prevent accidental data loss
Dependencies
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- oc_diagnostics (structured debug logging via _dbg)