refactor: codebase-wide lint cleanup — unused imports, dead code, and inefficient patterns (#5821)

Comprehensive cleanup across 80 files based on automated (ruff, pyflakes, vulture)
and manual analysis of the entire codebase.

Changes by category:

Unused imports removed (~95 across 55 files):
- Removed genuinely unused imports from all major subsystems
- agent/, hermes_cli/, tools/, gateway/, plugins/, cron/
- Includes imports in try/except blocks that were truly unused
  (vs availability checks which were left alone)

Unused variables removed (~25):
- Removed dead variables: connected, inner, channels, last_exc,
  source, new_server_names, verify, pconfig, default_terminal,
  result, pending_handled, temperature, loop
- Dropped unused argparse subparser assignments in hermes_cli/main.py
  (12 instances of add_parser() where result was never used)

Dead code removed:
- run_agent.py: Removed dead ternary (None if False else None) and
  surrounding unreachable branch in identity fallback
- run_agent.py: Removed write-only attribute _last_reported_tool
- hermes_cli/providers.py: Removed dead @property decorator on
  module-level function (decorator has no effect outside a class)
- gateway/run.py: Removed unused MCP config load before reconnect
- gateway/platforms/slack.py: Removed dead SessionSource construction

Undefined name bugs fixed (would cause NameError at runtime):
- batch_runner.py: Added missing logger = logging.getLogger(__name__)
- tools/environments/daytona.py: Added missing Dict and Path imports

Unnecessary global statements removed (14):
- tools/terminal_tool.py: 5 functions declared global for dicts
  they only mutated via .pop()/[key]=value (no rebinding)
- tools/browser_tool.py: cleanup thread loop only reads flag
- tools/rl_training_tool.py: 4 functions only do dict mutations
- tools/mcp_oauth.py: only reads the global
- hermes_time.py: only reads cached values

Inefficient patterns fixed:
- startswith/endswith tuple form: 15 instances of
  x.startswith('a') or x.startswith('b') consolidated to
  x.startswith(('a', 'b'))
- len(x)==0 / len(x)>0: 13 instances replaced with pythonic
  truthiness checks (not x / bool(x))
- in dict.keys(): 5 instances simplified to in dict
- Redefined unused name: removed duplicate _strip_mdv2 import in
  send_message_tool.py

Other fixes:
- hermes_cli/doctor.py: Replaced undefined logger.debug() with pass
- hermes_cli/config.py: Consolidated chained .endswith() calls

Test results: 3934 passed, 17 failed (all pre-existing on main),
19 skipped. Zero regressions.

hermes_cli/main.py

@@ -1154,7 +1154,7 @@ def _model_flow_nous(config, current_model="", args=None):
     from hermes_cli.auth import (
         get_provider_auth_state, _prompt_model_selection, _save_model_choice,
         _update_config_for_provider, resolve_nous_runtime_credentials,
-        fetch_nous_models, AuthError, format_auth_error,
+        AuthError, format_auth_error,
         _login_nous, PROVIDER_REGISTRY,
     )
     from hermes_cli.config import get_env_value, save_config, save_env_value
@@ -1314,7 +1314,6 @@ def _model_flow_openai_codex(config, current_model=""):
         PROVIDER_REGISTRY, DEFAULT_CODEX_BASE_URL,
     )
     from hermes_cli.codex_models import get_codex_model_ids
-    from hermes_cli.config import get_env_value, save_env_value
     import argparse
 
     status = get_codex_auth_status()
@@ -1367,7 +1366,7 @@ def _model_flow_custom(config):
     so it appears in the provider menu on subsequent runs.
     """
     from hermes_cli.auth import _save_model_choice, deactivate_provider
-    from hermes_cli.config import get_env_value, save_env_value, load_config, save_config
+    from hermes_cli.config import get_env_value, load_config, save_config
 
     current_url = get_env_value("OPENAI_BASE_URL") or ""
     current_key = get_env_value("OPENAI_API_KEY") or ""
@@ -1629,7 +1628,7 @@ def _model_flow_named_custom(config, provider_info):
     Otherwise probes the endpoint's /models API to let the user pick one.
     """
     from hermes_cli.auth import _save_model_choice, deactivate_provider
-    from hermes_cli.config import save_env_value, load_config, save_config
+    from hermes_cli.config import load_config, save_config
     from hermes_cli.models import fetch_api_models
 
     name = provider_info["name"]
@@ -1839,7 +1838,7 @@ def _model_flow_copilot(config, current_model=""):
         deactivate_provider,
         resolve_api_key_provider_credentials,
     )
-    from hermes_cli.config import get_env_value, save_env_value, load_config, save_config
+    from hermes_cli.config import save_env_value, load_config, save_config
     from hermes_cli.models import (
         fetch_api_models,
         fetch_github_model_catalog,
@@ -2430,8 +2429,6 @@ def _model_flow_anthropic(config, current_model=""):
     )
     from hermes_cli.models import _PROVIDER_MODELS
 
-    pconfig = PROVIDER_REGISTRY["anthropic"]
-
     # Check ALL credential sources
     existing_key = (
         get_env_value("ANTHROPIC_TOKEN")
@@ -3700,7 +3697,7 @@ def cmd_update(args):
         try:
             from hermes_cli.gateway import (
                 is_macos, is_linux, _ensure_user_systemd_env,
-                get_systemd_linger_status, find_gateway_pids,
+                find_gateway_pids,
                 _get_service_pids,
             )
             import signal as _signal
@@ -3856,7 +3853,7 @@ def cmd_profile(args):
     """Profile management — create, delete, list, switch, alias."""
     from hermes_cli.profiles import (
         list_profiles, create_profile, delete_profile, seed_profile_skills,
-        get_active_profile, set_active_profile, get_active_profile_name,
+        set_active_profile, get_active_profile_name,
         check_alias_collision, create_wrapper_script, remove_wrapper_script,
         _is_wrapper_dir_in_path, _get_wrapper_dir,
     )
@@ -3984,7 +3981,6 @@ def cmd_profile(args):
             print(f"  {name} chat               Start chatting")
             print(f"  {name} gateway start      Start the messaging gateway")
             if clone or clone_all:
-                from hermes_constants import get_hermes_home
                 profile_dir_display = f"~/.hermes/profiles/{name}"
                 print(f"\n  Edit {profile_dir_display}/.env for different API keys")
                 print(f"  Edit {profile_dir_display}/SOUL.md for different personality")
@@ -4407,7 +4403,7 @@ For more help on a command:
     gateway_uninstall.add_argument("--system", action="store_true", help="Target the Linux system-level gateway service")
 
     # gateway setup
-    gateway_setup = gateway_subparsers.add_parser("setup", help="Configure messaging platforms")
+    gateway_subparsers.add_parser("setup", help="Configure messaging platforms")
 
     gateway_parser.set_defaults(func=cmd_gateway)
     
@@ -4682,10 +4678,10 @@ For more help on a command:
     config_subparsers = config_parser.add_subparsers(dest="config_command")
     
     # config show (default)
-    config_show = config_subparsers.add_parser("show", help="Show current configuration")
+    config_subparsers.add_parser("show", help="Show current configuration")
     
     # config edit
-    config_edit = config_subparsers.add_parser("edit", help="Open config file in editor")
+    config_subparsers.add_parser("edit", help="Open config file in editor")
     
     # config set
     config_set = config_subparsers.add_parser("set", help="Set a configuration value")
@@ -4693,16 +4689,16 @@ For more help on a command:
     config_set.add_argument("value", nargs="?", help="Value to set")
     
     # config path
-    config_path = config_subparsers.add_parser("path", help="Print config file path")
+    config_subparsers.add_parser("path", help="Print config file path")
     
     # config env-path
-    config_env = config_subparsers.add_parser("env-path", help="Print .env file path")
+    config_subparsers.add_parser("env-path", help="Print .env file path")
     
     # config check
-    config_check = config_subparsers.add_parser("check", help="Check for missing/outdated config")
+    config_subparsers.add_parser("check", help="Check for missing/outdated config")
     
     # config migrate
-    config_migrate = config_subparsers.add_parser("migrate", help="Update config with new options")
+    config_subparsers.add_parser("migrate", help="Update config with new options")
     
     config_parser.set_defaults(func=cmd_config)
     
@@ -4716,7 +4712,7 @@ For more help on a command:
     )
     pairing_sub = pairing_parser.add_subparsers(dest="pairing_action")
 
-    pairing_list_parser = pairing_sub.add_parser("list", help="Show pending + approved users")
+    pairing_sub.add_parser("list", help="Show pending + approved users")
 
     pairing_approve_parser = pairing_sub.add_parser("approve", help="Approve a pairing code")
     pairing_approve_parser.add_argument("platform", help="Platform name (telegram, discord, slack, whatsapp)")
@@ -4726,7 +4722,7 @@ For more help on a command:
     pairing_revoke_parser.add_argument("platform", help="Platform name")
     pairing_revoke_parser.add_argument("user_id", help="User ID to revoke")
 
-    pairing_clear_parser = pairing_sub.add_parser("clear-pending", help="Clear all pending codes")
+    pairing_sub.add_parser("clear-pending", help="Clear all pending codes")
 
     def cmd_pairing(args):
         from hermes_cli.pairing import pairing_command
@@ -4902,7 +4898,7 @@ For more help on a command:
     memory_sub = memory_parser.add_subparsers(dest="memory_command")
     memory_sub.add_parser("setup", help="Interactive provider selection and configuration")
     memory_sub.add_parser("status", help="Show current memory provider config")
-    memory_off_p = memory_sub.add_parser("off", help="Disable external provider (built-in only)")
+    memory_sub.add_parser("off", help="Disable external provider (built-in only)")
 
     def cmd_memory(args):
         sub = getattr(args, "memory_command", None)
@@ -5066,7 +5062,7 @@ For more help on a command:
     sessions_prune.add_argument("--source", help="Only prune sessions from this source")
     sessions_prune.add_argument("--yes", "-y", action="store_true", help="Skip confirmation")
 
-    sessions_stats = sessions_subparsers.add_parser("stats", help="Show session store statistics")
+    sessions_subparsers.add_parser("stats", help="Show session store statistics")
 
     sessions_rename = sessions_subparsers.add_parser("rename", help="Set or change a session's title")
     sessions_rename.add_argument("session_id", help="Session ID to rename")
@@ -5426,7 +5422,7 @@ For more help on a command:
     )
     profile_subparsers = profile_parser.add_subparsers(dest="profile_action")
 
-    profile_list = profile_subparsers.add_parser("list", help="List all profiles")
+    profile_subparsers.add_parser("list", help="List all profiles")
     profile_use = profile_subparsers.add_parser("use", help="Set sticky default profile")
     profile_use.add_argument("profile_name", help="Profile name (or 'default')")