refactor(channels): make built-in channels self-contained (#4908)

* refactor(channels): own setup and instance contracts

* refactor(channels): isolate management contracts

* refactor(channels): normalize activation contracts

* fix(channels): enforce management contracts

* refactor(channels): finish setup ownership migration

* fix(channels): harden management contracts

* fix(channels): enforce lazy loading and runtime ownership

* fix(feishu): make multi-instance startup idempotent

* fix(webui): render channel setup contracts cleanly

* fix(feishu): stop websocket clients cleanly

* fix(channels): enforce persistence and activation gates

* fix(channels): preserve global feature action scope

* fix(channels): apply defaults for single plugins

* fix(channels): enforce management contract boundaries

* refactor(feishu): remove identity helper indirection

* fix(channels): preserve management setup contracts

* refactor(channels): generalize instance settings UI

* refactor(channels): package channel plugins with web UI metadata

* refactor(channels): make built-ins self-contained packages

* test(channels): colocate tests with channel packages

* fix(dingtalk): use official brand icon

* feat(channels): colocate webui translations

* docs(channels): clarify plugin ownership

* test(exec): remove output wait race

* refactor(channels): unify plugin descriptors

* fix(channels): enforce descriptor-owned contracts

* refactor(channels): finish package-owned plugin setup

* refactor(channels): use repository-owned packages only

* fix(channels): self-describe dependencies and runtime state

* fix(channels): warn about legacy entry points

tests/config/test_config_migration.py

@@ -131,7 +131,7 @@ def test_save_config_drops_legacy_max_messages(tmp_path) -> None:
 
 
 def test_onboard_refresh_backfills_missing_channel_fields(tmp_path, monkeypatch) -> None:
-    from types import SimpleNamespace
+    from nanobot.channels.plugin import load_channel_package
 
     config_path = tmp_path / "config.json"
     workspace = tmp_path / "workspace"
@@ -153,19 +153,13 @@ def test_onboard_refresh_backfills_missing_channel_fields(tmp_path, monkeypatch)
 
     monkeypatch.setattr("nanobot.config.loader.get_config_path", lambda: config_path)
     monkeypatch.setattr("nanobot.cli.commands.get_workspace_path", lambda _workspace=None: workspace)
+    monkeypatch.setattr(
+        "nanobot.channels.registry.discover_plugins",
+        lambda: {"qq": load_channel_package("qq")},
+    )
     monkeypatch.setattr(
         "nanobot.channels.registry.discover_all",
-        lambda: {
-            "qq": SimpleNamespace(
-                default_config=lambda: {
-                    "enabled": False,
-                    "appId": "",
-                    "secret": "",
-                    "allowFrom": [],
-                    "msgFormat": "plain",
-                }
-            )
-        },
+        lambda: pytest.fail("onboarding must not import channel runtimes"),
     )
 
     from typer.testing import CliRunner