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/setup.py

@@ -283,7 +283,6 @@ from hermes_cli.config import (
     save_env_value,
     get_env_value,
     ensure_hermes_home,
-    DEFAULT_CONFIG,
 )
 
 from hermes_cli.colors import Colors, color
@@ -798,15 +797,11 @@ def setup_model_provider(config: dict):
     """Configure the inference provider and default model."""
     from hermes_cli.auth import (
         get_active_provider,
-        get_provider_auth_state,
         PROVIDER_REGISTRY,
-        format_auth_error,
-        AuthError,
         fetch_nous_models,
         resolve_nous_runtime_credentials,
         _update_config_for_provider,
         _login_openai_codex,
-        get_codex_auth_status,
         resolve_codex_runtime_credentials,
         DEFAULT_CODEX_BASE_URL,
         detect_external_credentials,
@@ -975,7 +970,7 @@ def setup_model_provider(config: dict):
         print()
 
         try:
-            from hermes_cli.auth import _login_nous, ProviderConfig
+            from hermes_cli.auth import _login_nous
             import argparse
 
             mock_args = argparse.Namespace(
@@ -3303,7 +3298,6 @@ def _run_quick_setup(config: dict, hermes_home):
         get_missing_env_vars,
         get_missing_config_fields,
         check_config_version,
-        migrate_config,
     )
 
     print()