feat(cli): add --ignore-user-config and --ignore-rules flags

Port from openai/codex#18646.

Adds two flags to 'hermes chat' that fully isolate a run from user-level
configuration and rules:

* --ignore-user-config: skip ~/.hermes/config.yaml and fall back to
  built-in defaults. Credentials in .env are still loaded so the agent
  can actually call a provider.
* --ignore-rules: skip auto-injection of AGENTS.md, SOUL.md,
  .cursorrules, and persistent memory (maps to AIAgent(skip_context_files=True,
  skip_memory=True)).

Primary use cases:
- Reproducible CI runs that should not pick up developer-local config
- Third-party integrations (e.g. Chronicle in Codex) that bring their
  own config and don't want user preferences leaking in
- Bug-report reproduction without the reporter's personal overrides
- Debugging: bisect 'was it my config?' vs 'real bug' in one command

Both flags are registered on the parent parser AND the 'chat' subparser
(with argparse.SUPPRESS on the subparser to avoid overwriting the parent
value when the flag is placed before the subcommand, matching the
existing --yolo/--worktree/--pass-session-id pattern).

Env vars HERMES_IGNORE_USER_CONFIG=1 and HERMES_IGNORE_RULES=1 are set
by cmd_chat BEFORE 'from cli import main' runs, which is critical
because cli.py evaluates CLI_CONFIG = load_cli_config() at module import
time. The cli.py / hermes_cli.config.load_cli_config() function checks
the env var and skips ~/.hermes/config.yaml when set.

Tests: 11 new tests in tests/hermes_cli/test_ignore_user_config_flags.py
covering the env gate, constructor wiring, cmd_chat simulation, and
argparse flag registration. All pass; existing hermes_cli + cli suites
unaffected (3005 pass, 2 pre-existing unrelated failures).

hermes_cli/main.py

@@ -1131,6 +1131,20 @@ def cmd_chat(args):
     if getattr(args, "yolo", False):
         os.environ["HERMES_YOLO_MODE"] = "1"
 
+    # --ignore-user-config: make load_cli_config() / load_config() skip the
+    # user's ~/.hermes/config.yaml and return built-in defaults. Set BEFORE
+    # importing cli (which runs `CLI_CONFIG = load_cli_config()` at module
+    # import time). Credentials in .env are still loaded — this flag only
+    # ignores behavioral/config settings.
+    if getattr(args, "ignore_user_config", False):
+        os.environ["HERMES_IGNORE_USER_CONFIG"] = "1"
+
+    # --ignore-rules: skip auto-injection of AGENTS.md/SOUL.md/.cursorrules
+    # (rules), memory entries, and any preloaded skills coming from user config.
+    # Maps to AIAgent(skip_context_files=True, skip_memory=True).
+    if getattr(args, "ignore_rules", False):
+        os.environ["HERMES_IGNORE_RULES"] = "1"
+
     # --source: tag session source for filtering (e.g. 'tool' for third-party integrations)
     if getattr(args, "source", None):
         os.environ["HERMES_SESSION_SOURCE"] = args.source
@@ -1159,6 +1173,8 @@ def cmd_chat(args):
         "checkpoints": getattr(args, "checkpoints", False),
         "pass_session_id": getattr(args, "pass_session_id", False),
         "max_turns": getattr(args, "max_turns", None),
+        "ignore_rules": getattr(args, "ignore_rules", False),
+        "ignore_user_config": getattr(args, "ignore_user_config", False),
     }
     # Filter out None values
     kwargs = {k: v for k, v in kwargs.items() if v is not None}
@@ -6606,6 +6622,18 @@ For more help on a command:
         default=False,
         help="Include the session ID in the agent's system prompt",
     )
+    parser.add_argument(
+        "--ignore-user-config",
+        action="store_true",
+        default=False,
+        help="Ignore ~/.hermes/config.yaml and fall back to built-in defaults (credentials in .env are still loaded)",
+    )
+    parser.add_argument(
+        "--ignore-rules",
+        action="store_true",
+        default=False,
+        help="Skip auto-injection of AGENTS.md, SOUL.md, .cursorrules, memory, and preloaded skills",
+    )
     parser.add_argument(
         "--tui",
         action="store_true",
@@ -6745,6 +6773,18 @@ For more help on a command:
         default=argparse.SUPPRESS,
         help="Include the session ID in the agent's system prompt",
     )
+    chat_parser.add_argument(
+        "--ignore-user-config",
+        action="store_true",
+        default=argparse.SUPPRESS,
+        help="Ignore ~/.hermes/config.yaml and fall back to built-in defaults (credentials in .env are still loaded). Useful for isolated CI runs, reproduction, and third-party integrations.",
+    )
+    chat_parser.add_argument(
+        "--ignore-rules",
+        action="store_true",
+        default=argparse.SUPPRESS,
+        help="Skip auto-injection of AGENTS.md, SOUL.md, .cursorrules, memory, and preloaded skills. Combine with --ignore-user-config for a fully isolated run.",
+    )
     chat_parser.add_argument(
         "--source",
         default=None,