refactor: split precheck_core and migrate commands to commands/

- Split 900-line precheck_core.py into 9 focused modules:
  precheck_constants, time_utils, data_utils, state_manager,
  market_data, candidate_scoring, snapshot_builder,
  adaptive_profile, trigger_analyzer
- Remove dead auto_trader command and module
- Migrate 7 root-level command modules into commands/:
  check_api, doctor, external_gate, init_user_state,
  market_probe, paths, rotate_external_gate_log
- Keep thin backward-compatible facades in root package
- Update cli.py MODULE_MAP to route through commands/
- Verified compileall and smoke tests for all key commands

README.md

@@ -168,6 +168,20 @@ coinhunter external-gate
 coinhunter rotate-external-gate-log
 ```
 
+Supported top-level commands and aliases remain:
+
+- `check-api` / `api-check`
+- `doctor` / `diag`
+- `external-gate` / `gate`
+- `init`
+- `market-probe` / `probe`
+- `paths`
+- `precheck`
+- `review-context` / `review`
+- `review-engine` / `recap`
+- `rotate-external-gate-log` / `rotate-gate-log` / `rotate-log`
+- `smart-executor` / `exec`
+
 ## Runtime model
 
 Default layout: