Merge branch 'stack/agent-profiles-5-web-ui' into stack/agent-profiles-8-authoring

The composer's preset seat stays removed here — this layer moved it to the
hero chip and the session-header action — so only the model seat takes the
`modelSeatLocked` narrowing master introduced.

Conflicts:
	apps/web/tests/snapshots/*/*.expected.md
	packages/client/connection/README.md
	packages/client/connection/README.zh.md
	packages/client/ui-conversation/src/client/skeleton/InputBar.tsx
	packages/host/apiproxy/src/fetch/client.ts

apps/web/tsconfig.json

@@ -37,6 +37,7 @@
     "tests/details-session-lifecycle.e2e.ts",
     "tests/settings-chrome.e2e.ts",
     "tests/models-settings.e2e.ts",
+    "tests/default-model.e2e.ts",
     "tests/onboarding-deepseek-config.e2e.ts",
     "tests/remote-welcome.e2e.ts",
     "tests/workspace-management.e2e.ts",
@@ -60,8 +61,9 @@
     "tests/access-confirmation.e2e.ts",
     "tests/agent-preset-selection.e2e.ts",
     "tests/shipped-composition.e2e.ts",
-    "tests/goal-bar.e2e.ts",
     "tests/startup-auto-selection.e2e.ts",
+    "tests/produced-files.e2e.ts",
+    "tests/goal-bar.e2e.ts",
     "tests/subagent-conversation.e2e.ts",
     "tests/bash-abort-row.e2e.ts",
     "tests/skill-tool-row.e2e.ts",