chore: remove ~100 unused imports across 55 files (#3016)

Automated cleanup via pyflakes + autoflake with manual review.

Changes:
- Removed unused stdlib imports (os, sys, json, pathlib.Path, etc.)
- Removed unused typing imports (List, Dict, Any, Optional, Tuple, Set, etc.)
- Removed unused internal imports (hermes_cli.auth, hermes_cli.config, etc.)
- Fixed cli.py: removed 8 shadowed banner imports (imported from hermes_cli.banner
  then immediately redefined locally — only build_welcome_banner is actually used)
- Added noqa comments to imports that appear unused but serve a purpose:
  - Re-exports (gateway/session.py SessionResetPolicy, tools/terminal_tool.py
    is_interrupted/_interrupt_event)
  - SDK presence checks in try/except (daytona, fal_client, discord)
  - Test mock targets (auxiliary_client.py Path, mcp_config.py get_hermes_home)

Zero behavioral changes. Full test suite passes (6162/6162, 2 pre-existing
streaming test failures unrelated to this change).

hermes_cli/doctor.py

@@ -8,7 +8,6 @@ import os
 import sys
 import subprocess
 import shutil
-from pathlib import Path
 
 from hermes_cli.config import get_project_root, get_hermes_home, get_env_path
 
@@ -448,7 +447,7 @@ def run_doctor(args):
             check_fail("DAYTONA_API_KEY not set", "(required for TERMINAL_ENV=daytona)")
             issues.append("Set DAYTONA_API_KEY environment variable")
         try:
-            from daytona import Daytona
+            from daytona import Daytona  # noqa: F401 — SDK presence check
             check_ok("daytona SDK", "(installed)")
         except ImportError:
             check_fail("daytona SDK not installed", "(pip install daytona)")