refactor(model_switch): remove parse_model_flags, which only tests called

Every /model surface parses through parse_model_switch_args. The legacy
5-tuple wrapper had no production caller; its remaining references were two
tests of the tuple shape, an unused import, and two tui_gateway patch()
calls on a function tui_gateway no longer calls.

The en-dash --session normalization those tests covered moves into the
parse_model_switch_args keeper. test_model_switch_once_flags and
test_model_switch_context_offload are removed: the first re-tests the
private parser the keeper already drives, the second the one-line to_thread
wrapper that tests/gateway/test_model_command_context_offload.py proves off
the event loop through the real /model handler.

hermes_cli/model_switch.py

@@ -507,12 +507,6 @@ def parse_model_flags_detailed(raw_args: str) -> ModelFlagParseResult:
     return ModelFlagParseResult(model_input=" ".join(filtered).strip(), **values, **flags)
 
 
-def parse_model_flags(raw_args: str) -> tuple[str, str, bool, bool, bool]:
-    """Legacy 5-tuple ``(model_input, explicit_provider, is_global, force_refresh, is_session)``."""
-    p = parse_model_flags_detailed(raw_args)
-    return (p.model_input, p.explicit_provider, p.is_global, p.force_refresh, p.is_session)
-
-
 def resolve_persist_behavior(
     is_global: bool, is_session: bool, is_once: bool = False, explicit_provider: str = "") -> bool:
     """Decide whether a ``/model`` switch should persist to ``config.yaml``.

tests/hermes_cli/test_kimi_cn_provider_listing.py

@@ -16,7 +16,6 @@ from unittest.mock import patch
 
 from hermes_cli.model_switch import (
     list_authenticated_providers,
-    parse_model_flags,
     switch_model,
 )
 from hermes_cli.providers import resolve_provider_full

tests/hermes_cli/test_model_switch_context_offload.py

@@ -1,63 +0,0 @@
-"""``/model`` context-length resolution must not run on the gateway event loop.
-
-``resolve_display_context_length`` runs two blocking chains — the route
-comparison in ``should_clear_context_pin`` and the provider probe ladder in
-``get_model_context_length`` (blocking ``requests`` calls to Anthropic
-``/v1/models``, Copilot, Nous, Codex, GMI, Ollama, models.dev and OpenRouter).
-
-The gateway message path already offloads both (``get_model_context_length_async``,
-``should_clear_context_pin_async``); the ``/model`` slash-command handlers called
-the sync helper directly, freezing the loop for every user on every platform for
-the duration of the probe ladder.
-"""
-
-import threading
-import time
-
-import pytest
-
-import agent.model_metadata as model_meta_mod
-from hermes_cli import model_switch
-
-PROBE_SECONDS = 0.05
-
-RESOLVE_ARGS = dict(
-    model="claude-opus-4",
-    provider="anthropic",
-    base_url="",
-    api_key="",
-    custom_providers=None,
-    config_context_length=None,
-)
-
-
-@pytest.fixture
-def slow_probe(monkeypatch):
-    """Stand in for one blocking provider probe inside the resolution chain."""
-    calls = {}
-
-    def _probe(model, **kwargs):
-        calls["thread"] = threading.current_thread()
-        time.sleep(PROBE_SECONDS)
-        return 128000
-
-    monkeypatch.setattr(model_meta_mod, "get_model_context_length", _probe)
-    return calls
-
-
-@pytest.mark.asyncio
-async def test_async_variant_matches_sync(slow_probe):
-    """The async wrapper resolves the same value as the sync helper."""
-    sync_value = model_switch.resolve_display_context_length(**RESOLVE_ARGS)
-    async_value = await model_switch.resolve_display_context_length_async(
-        **RESOLVE_ARGS
-    )
-    assert async_value == sync_value == 128000
-
-
-@pytest.mark.asyncio
-async def test_resolution_runs_off_the_event_loop_thread(slow_probe):
-    """The blocking chain must execute on a worker thread, not the loop thread."""
-    loop_thread = threading.current_thread()
-    await model_switch.resolve_display_context_length_async(**RESOLVE_ARGS)
-    assert slow_probe["thread"] is not loop_thread

tests/hermes_cli/test_model_switch_once_flags.py

@@ -1,14 +0,0 @@
-from hermes_cli.model_switch import parse_model_flags, parse_model_flags_detailed
-
-
-def test_parse_model_flags_detailed_supports_once():
-    parsed = parse_model_flags_detailed("sonnet --provider anthropic --once")
-
-    assert parsed.model_input == "sonnet"
-    assert parsed.explicit_provider == "anthropic"
-    assert parsed.is_global is False
-    assert parsed.force_refresh is False
-    assert parsed.is_session is False
-    assert parsed.is_once is True
-
-

tests/hermes_cli/test_model_switch_parsing.py

@@ -22,6 +22,7 @@ def test_provider_flag_and_scopes():
     assert req.errors == ()
 
     assert parse_model_switch_args("sonnet --session").scope == "session"
+    assert parse_model_switch_args("sonnet \u2013session").scope == "session"  # iOS/Telegram en-dash
     assert parse_model_switch_args("sonnet --once").scope == "once"
     assert parse_model_switch_args("--refresh").force_refresh is True
 

tests/hermes_cli/test_model_switch_persist_default.py

@@ -1,7 +1,6 @@
 """Tests for session-scoped-by-default model switching.
 
 Covers:
-- ``parse_model_flags`` recognises ``--session`` (and keeps ``--global``).
 - ``resolve_persist_behavior`` applies the config-gated default and the
   ``--session`` / ``--global`` overrides.
 - The default (no flags) is session-only, which is the user-facing fix: a
@@ -11,28 +10,7 @@ Covers:
 
 from unittest.mock import patch
 
-from hermes_cli.model_switch import parse_model_flags, resolve_persist_behavior
-
-
-# ---------------------------------------------------------------------------
-# parse_model_flags
-# ---------------------------------------------------------------------------
-
-
-class TestParseModelFlagsSession:
-    def test_no_flags(self):
-        assert parse_model_flags("sonnet") == ("sonnet", "", False, False, False)
-
-
-    def test_unicode_dash_session_normalized(self):
-        # Telegram/iOS auto-converts -- to en/em dashes.
-        assert parse_model_flags("sonnet \u2013session") == (
-            "sonnet",
-            "",
-            False,
-            False,
-            True,
-        )
+from hermes_cli.model_switch import resolve_persist_behavior
 
 
 # ---------------------------------------------------------------------------

tests/tui_gateway/test_custom_provider_session_persistence.py

@@ -635,7 +635,6 @@ class TestFollowProfileConfigRuntimeOverrides:
         known = set(server._sessions)
         try:
             with (
-                patch("hermes_cli.model_switch.parse_model_flags", return_value=("glm-5.1", None, False, False, None)),
                 patch("hermes_cli.model_switch.resolve_persist_behavior", return_value=False),
                 patch("hermes_cli.model_switch.switch_model", return_value=result),
                 server._profile_build_scope(secondary),

tests/tui_gateway/test_make_agent_provider.py

@@ -68,8 +68,6 @@ def test_apply_model_switch_does_not_leak_process_env():
 
     persisted_composer_profiles = []
     with (
-        patch("hermes_cli.model_switch.parse_model_flags",
-              return_value=("glm-5.1", None, False, False, True)),
         patch("hermes_cli.model_switch.resolve_persist_behavior",
               return_value=False),
         patch("hermes_cli.model_switch.switch_model", return_value=_FakeResult()),