Move sessionHistoryMaxMessages, sessionHistoryMaxTokens, and
sessionFileMaxMessages out of user-facing config into internal
constants (HISTORY_MAX_MESSAGES=120, FILE_MAX_MESSAGES=2000).
- Remove 3 fields from AgentDefaults and config pipeline
- Sink enforce_file_cap into Session (was AgentLoop)
- Auto-derive token budget from context window (was configurable)
- Net -113 lines across 7 files; 723 tests green
Made-with: Cursor