test(client): cover the fixture noteAgentPreset write-back; refresh the module graph

The stub's confirmed-switch write-back landed with the header-label work
but nothing exercised it, and the module graph regen after the master
merge had been swallowed by a silenced generator run.

docs/module-graph.md

@@ -26,6 +26,7 @@ flowchart TD
   subgraph group_core["packages/core"]
     pkg_agent["agent"]
     pkg_agent_loop["agent-loop"]
+    pkg_agent_tool_mode["agent-tool-mode"]
     pkg_scope["scope"]
     pkg_session["session"]
     pkg_system_prompt["system-prompt"]
@@ -500,6 +501,7 @@ flowchart TD
   pkg_code_runtime_worker --> pkg_invariants
   pkg_code_runtime_worker --> pkg_session
   pkg_code_runtime_worker --> pkg_timeout
+  pkg_agent_presets --> pkg_atomic_write
   pkg_agent_presets --> pkg_invariants
   pkg_agent_presets --> pkg_paths
   pkg_agent_presets --> pkg_scope
@@ -764,6 +766,8 @@ flowchart TD
   pkg_agent_loop --> pkg_session_persistence
   pkg_agent_loop --> pkg_system_prompt
   pkg_agent_loop --> pkg_tools
+  pkg_agent_tool_mode --> pkg_invariants
+  pkg_agent_tool_mode --> pkg_tools
   pkg_tool_goal --> pkg_agent
   pkg_tool_goal --> pkg_goal
   pkg_tool_goal --> pkg_invariants
@@ -903,7 +907,9 @@ flowchart TD
   pkg_client_ui_agent_preset --> pkg_client_runtime
   pkg_client_ui_agent_preset --> pkg_client_ui_conversation
   pkg_client_ui_agent_preset --> pkg_client_ui_primitives
+  pkg_client_ui_agent_preset --> pkg_client_ui_settings
   pkg_client_ui_agent_preset --> pkg_client_ui_slots
+  pkg_client_ui_agent_preset --> pkg_client_web_react
   pkg_client_ui_agent_preset --> pkg_invariants
   pkg_client_ui_command --> pkg_client_connection
   pkg_client_ui_command --> pkg_client_locale
@@ -1272,7 +1278,7 @@ flowchart TD
 | [`client-ui-theme`](../packages/client/ui-theme) | `client` | [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-primitives`](../packages/client/ui-primitives), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
 | [`client-ui-workspace`](../packages/client/ui-workspace) | `client` | [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-primitives`](../packages/client/ui-primitives), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
 | [`code-runtime-worker`](../packages/code-runtime/code-runtime-worker) | `code-runtime` | [`code-runtime`](../packages/code-runtime/code-runtime), [`invariants`](../packages/support/invariants), [`session`](../packages/core/session), [`timeout`](../packages/util/timeout) |
-| [`agent-presets`](../packages/preset/agent-presets) | `preset` | [`invariants`](../packages/support/invariants), [`paths`](../packages/util/paths), [`scope`](../packages/core/scope), [`session`](../packages/core/session), [`settings`](../packages/settings/settings) |
+| [`agent-presets`](../packages/preset/agent-presets) | `preset` | [`atomic-write`](../packages/util/atomic-write), [`invariants`](../packages/support/invariants), [`paths`](../packages/util/paths), [`scope`](../packages/core/scope), [`session`](../packages/core/session), [`settings`](../packages/settings/settings) |
 | [`persona`](../packages/preset/persona) | `preset` | [`invariants`](../packages/support/invariants), [`system-prompt`](../packages/core/system-prompt) |
 | [`sandbox-local`](../packages/sandbox/sandbox-local) | `sandbox` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`sandbox`](../packages/sandbox/sandbox) |
 | [`session-projection`](../packages/session-projection/session-projection) | `session-projection` | [`invariants`](../packages/support/invariants), [`session`](../packages/core/session) |
@@ -1331,6 +1337,7 @@ flowchart TD
 | [`pty-local`](../packages/pty/pty-local) | `pty` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`pty`](../packages/pty/pty), [`sandbox`](../packages/sandbox/sandbox), [`sandbox-policy`](../packages/sandbox/sandbox-policy), [`session`](../packages/core/session), [`subprocess`](../packages/subprocess/subprocess) |
 | [`tasks-local`](../packages/tasks/tasks-local) | `tasks` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`tasks`](../packages/tasks/tasks), [`timeout`](../packages/util/timeout) |
 | [`agent-loop`](../packages/core/agent-loop) | `core` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`scope`](../packages/core/scope), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`system-prompt`](../packages/core/system-prompt), [`tools`](../packages/core/tools) |
+| [`agent-tool-mode`](../packages/core/agent-tool-mode) | `core` | [`invariants`](../packages/support/invariants), [`tools`](../packages/core/tools) |
 | [`tool-goal`](../packages/goal/tool-goal) | `goal` | [`agent`](../packages/core/agent), [`goal`](../packages/goal/goal), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`system-prompt`](../packages/core/system-prompt), [`tools`](../packages/core/tools) |
 | [`bash-env`](../packages/bash/bash-env) | `bash` | [`bash`](../packages/bash/bash), [`invariants`](../packages/support/invariants), [`paths`](../packages/util/paths), [`session-persistence`](../packages/session-persistence/session-persistence), [`tools`](../packages/core/tools) |
 | [`tool-fs`](../packages/fs/tool-fs) | `fs` | [`fs`](../packages/fs/fs), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`sandbox`](../packages/sandbox/sandbox), [`sandbox-policy`](../packages/sandbox/sandbox-policy), [`session`](../packages/core/session), [`system-prompt`](../packages/core/system-prompt), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
@@ -1353,7 +1360,7 @@ flowchart TD
 | [`session-title-first-message-llm`](../packages/session-title/session-title-first-message-llm) | `session-title` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-title`](../packages/session-title/session-title), [`session-title-llm`](../packages/session-title/session-title-llm) |
 | [`agent-loop-testkit`](../packages/support/agent-loop-testkit) | `support` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`system-prompt`](../packages/core/system-prompt), [`tools`](../packages/core/tools) |
 | [`tool-ask-user`](../packages/ui/tool-ask-user) | `ui` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`tools`](../packages/core/tools), [`user-interaction`](../packages/ui/user-interaction) |
-| [`client-ui-agent-preset`](../packages/client/ui-agent-preset) | `client` | [`client-connection`](../packages/client/connection), [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-conversation`](../packages/client/ui-conversation), [`client-ui-primitives`](../packages/client/ui-primitives), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
+| [`client-ui-agent-preset`](../packages/client/ui-agent-preset) | `client` | [`client-connection`](../packages/client/connection), [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-conversation`](../packages/client/ui-conversation), [`client-ui-primitives`](../packages/client/ui-primitives), [`client-ui-settings`](../packages/client/ui-settings), [`client-ui-slots`](../packages/client/ui-slots), [`client-web-react`](../packages/client/web-react), [`invariants`](../packages/support/invariants) |
 | [`client-ui-command`](../packages/client/ui-command) | `client` | [`client-connection`](../packages/client/connection), [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-conversation`](../packages/client/ui-conversation), [`client-ui-primitives`](../packages/client/ui-primitives), [`client-ui-slash`](../packages/client/ui-slash), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
 | [`client-ui-deliverables`](../packages/client/ui-deliverables) | `client` | [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-conversation`](../packages/client/ui-conversation), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
 | [`client-ui-goal`](../packages/client/ui-goal) | `client` | [`api-remotes`](../packages/api/remotes), [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-conversation`](../packages/client/ui-conversation), [`client-ui-primitives`](../packages/client/ui-primitives), [`client-ui-slots`](../packages/client/ui-slots), [`goal`](../packages/goal/goal), [`invariants`](../packages/support/invariants) |

packages/client/test-runtime/tests/runtime.spec.tsx

@@ -220,6 +220,13 @@ describe('sessions', () => {
       .toMatchObject({ displayTitle: 'renamed', running: true })
     runtime.sessions.setSubagentCatalogOpen('s2' as SessionId, true)
     await runtime.sessions.refreshSubagents('s2' as SessionId)
+    // The confirmed-switch write-back lands on the row it names and ignores
+    // one the fixture never added, exactly as production's list upsert does.
+    runtime.sessions.noteAgentPreset('s1' as SessionId, 'minimal')
+    runtime.sessions.noteAgentPreset('missing' as SessionId, 'minimal')
+    await runtime.flush()
+    expect(runtime.sessions.list.getSnapshot().byId['s1' as SessionId])
+      .toMatchObject({ agentPreset: 'minimal' })
     runtime.sessions.open('s1' as SessionId)
     await runtime.flush()
     expect(runtime.sessions.list.getSnapshot().current).toBe('s1')