refactor(plugins): unify provider registration and unload paths in hermes_cli/plugins.py

hermes_cli/plugins.py (7193 -> 4961):
- _register_scoped_provider: one body for the 8 scope-keyed register_*_provider methods;
  _track_callback/_track_mapping_entry unify manager-mapping lease tracking (4 sites);
  _track_scoped_registration for the ownership ledger. Public method names, signatures,
  return values and warning strings unchanged.
- Manifest v2 type checks table-driven (_manifest_field_of_type); _unload_scoped split into
  _unload_target_keys + _reset_after_unload_all; _gate_manifest/_record_placeholder out of
  _discover_and_load_inner; _track_tool_override_policy/_attribute_registrations out of
  _load_plugin_scoped; bounded hook worker lifted into _run_hook_callback_bounded;
  prompt-section rendering extracted; resolve_pre_tool_block delegates to
  _dispatch_pre_tool_call_hooks; _evict_modules (3 sites); _remove_name_if_unowned and
  _nowait_plugin_set unify unowned-name cleanup and *_nowait probes.
- Dead (zero references outside their own test): unload_plugins, has_portable_mcp_servers,
  _classify_entrypoint_kind, _reset_event_bus, get_plugin_subscriptions,
  get_telegram_handler_factories, pass-through _restore_* helpers; _env_enabled is now an alias
  of utils.env_var_enabled (plugins/memory still imports it).
- Docstrings/comments compacted; contract sentences and rationale kept (multi-profile ledger
  keying, persistent auth-provider registration, capability declaration is not a grant).

tests/gateway/test_platform_plugin_handlers.py

@@ -138,8 +138,6 @@ class TestTelegramAlias:
         assert mgr.get_platform_handler_factories("telegram") == [
             (factory, "test_plugin")
         ]
-        # Legacy accessor still works.
-        assert mgr.get_telegram_handler_factories() == [(factory, "test_plugin")]
 
     def test_alias_non_callable_raises(self):
         _, ctx = _make_ctx()

tests/hermes_cli/test_plugin_event_bus.py

@@ -26,7 +26,6 @@ from hermes_cli.plugins import (
     PluginContext,
     PluginManager,
     PluginManifest,
-    get_plugin_subscriptions,
 )
 
 
@@ -339,35 +338,6 @@ def test_owner_removal_cancels_callback_already_snapshotted_in_queue():
     assert observed == []
 
 
-def test_event_bus_reset_cancels_queued_generation():
-    manager = _fresh_manager()
-    ctx_gate = _make_ctx(manager, "gate", key="gate")
-    ctx_a = _make_ctx(manager, "plugin_a", key="a")
-    ctx_b = _make_ctx(manager, "plugin_b", key="b")
-    entered = threading.Event()
-    release = threading.Event()
-    observed = []
-
-    def blocking(**payload):
-        entered.set()
-        release.wait(timeout=2.0)
-
-    ctx_gate.subscribe("b:ping", blocking)
-    ctx_a.subscribe("b:ping", lambda **payload: observed.append(payload))
-    assert ctx_b.emit("ping", {"value": 1}) == 2
-    assert entered.wait(timeout=1.0)
-    old_worker = manager._event_worker
-
-    manager._reset_event_bus()
-    release.set()
-    assert old_worker is not None
-    old_worker.join(timeout=2.0)
-
-    assert not old_worker.is_alive()
-    assert observed == []
-    assert manager._subscriptions == {}
-
-
 # ── 5. Recursion cap ─────────────────────────────────────────────────────────
 
 
@@ -465,23 +435,6 @@ def test_manifest_parse_absent_emits_listens(tmp_path):
     assert manifest.listens == []
 
 
-# ── Module-level accessor ────────────────────────────────────────────────────
-
-
-def test_get_plugin_subscriptions_accessor(monkeypatch):
-    from hermes_cli import plugins as plugins_mod
-
-    fresh = _fresh_manager()
-    monkeypatch.setattr(plugins_mod, "_ensure_plugins_discovered", lambda force=False: fresh)
-
-    ctx = _make_ctx(fresh, "plugin_a", key="a")
-    ctx.subscribe("b:ping", lambda **p: None)
-
-    subs = get_plugin_subscriptions()
-    assert "b:ping" in subs
-    assert len(subs["b:ping"]) == 1
-
-
 # ── 7. plugins show output includes emits/listens ────────────────────────────