refactor: address high-priority debt and publish to PyPI

- Fix TOCTOU race conditions by wrapping read-modify-write cycles
  under single-file locks in execution_state, portfolio_service,
  precheck_state, state_manager, and precheck_service.
- Add missing test coverage (96 tests total):
  - test_review_service.py (15 tests)
  - test_check_api.py (6 tests)
  - test_external_gate.py main branches (+10 tests)
  - test_trade_execution.py new commands (+8 tests)
- Unify all agent-consumed JSON messages to English.
- Config-ize hardcoded values (volume filter, schema_version) via
  get_user_config with sensible defaults.
- Add 1-hour TTL to exchange cache with force_new override.
- Add ruff and mypy to dev dependencies; fix all type errors.
- Add __all__ declarations to 11 service modules.
- Sync README with new commands, config tuning docs, and PyPI badge.
- Publish package as coinhunter==1.0.0 on PyPI with MIT license.
- Deprecate coinhunter-cli==1.0.1 with runtime warning.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/coinhunter/services/market_data.py

@@ -7,15 +7,12 @@ import os
 import ccxt
 
 from .data_utils import norm_symbol, to_float
-from .precheck_constants import BLACKLIST, MAX_PRICE_CAP, MIN_CHANGE_PCT
-from .time_utils import utc_now
 
 
 def get_exchange():
     from ..runtime import load_env_file
-    from .precheck_constants import ENV_FILE
 
-    load_env_file(ENV_FILE)
+    load_env_file()
     api_key = os.getenv("BINANCE_API_KEY")
     secret = os.getenv("BINANCE_API_SECRET")
     if not api_key or not secret: