feat(runtime-host): carry exact Connection identity in Session model targets

apps/desktop/src/main/__tests__/app-shell-first-send-cleanup.test.ts

@@ -175,6 +175,7 @@ describe('composer first-send cleanup', () => {
       const deps = {
         ...createActionsDeps(),
         newChatModel: {
+          llmConnectionId: 'connection-1',
           llmConnectionSlug: 'opencode-free',
           model: 'mimo-v2.5-free',
         },

apps/desktop/src/main/__tests__/app-shell-session-settings-actions.test.ts

@@ -44,6 +44,7 @@ function session(id: string): DesktopSessionSummary {
     hasUnread: false,
     status: 'active',
     backend: 'fake',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'e2e',
     connectionLocked: true,
     model: 'claude-sonnet',
@@ -216,6 +217,7 @@ describe('AppShell session settings actions', () => {
     const harness = createHarness();
 
     const modelChange = harness.actions.setSessionModel({
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'e2e',
       model: 'claude-opus',
     });
@@ -242,6 +244,7 @@ describe('AppShell session settings actions', () => {
     });
 
     const modelChange = harness.actions.setSessionModel({
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'e2e',
       model: 'claude-opus',
     });
@@ -260,6 +263,7 @@ describe('AppShell session settings actions', () => {
     const harness = createHarness();
 
     const modelChange = harness.actions.setSessionModel({
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'e2e',
       model: 'claude-opus',
     });
@@ -278,11 +282,13 @@ describe('AppShell session settings actions', () => {
     });
 
     const modelChange = harness.actions.setSessionModel({
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'relay',
       model: 'claude-sonnet',
     });
     harness.modelResult.resolve({
       ...session('session-a'),
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'relay',
     });
     await modelChange;
@@ -297,6 +303,7 @@ describe('AppShell session settings actions', () => {
     const harness = createHarness();
 
     const modelChange = harness.actions.setSessionModel({
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'e2e',
       model: 'claude-opus',
     });
@@ -318,6 +325,7 @@ describe('AppShell session settings actions', () => {
 
     const thinkingChange = harness.actions.setSessionThinkingLevel('high');
     await harness.actions.setSessionModel({
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'e2e',
       model: 'claude-opus',
     });
@@ -344,6 +352,7 @@ describe('AppShell session settings actions', () => {
     assert.deepEqual(harness.errorTargets, [{ sessionId: 'session-a' }]);
 
     const modelChange = harness.actions.setSessionModel({
+      llmConnectionId: 'connection-1',
       llmConnectionSlug: 'e2e',
       model: 'claude-opus',
     });

apps/desktop/src/main/__tests__/model-catalog-choices.test.ts

@@ -19,14 +19,16 @@
 
 import { strict as assert } from 'node:assert';
 import { describe, it } from 'node:test';
-import type { LlmConnection } from '@maka/core/llm-connections';
+import type { IdentifiedLlmConnection } from '@maka/core/llm-connections';
 import { buildChatModelChoices } from '@maka/core/chat-model-choice';
 import { pickNewChatModel } from '../../renderer/shell-chat-model-selection.js';
 
 function connection(
-  overrides: Partial<LlmConnection> & Pick<LlmConnection, 'slug' | 'providerType'>,
-): LlmConnection {
+  overrides: Partial<IdentifiedLlmConnection> &
+    Pick<IdentifiedLlmConnection, 'slug' | 'providerType'>,
+): IdentifiedLlmConnection {
   return {
+    connectionId: `connection-${overrides.slug}`,
     name: overrides.slug,
     defaultModel: '',
     enabled: true,
@@ -49,6 +51,7 @@ describe('model catalog picker helpers', () => {
         catalogDefault: undefined,
         choices: [
           {
+            connectionId: 'connection-missing',
             connectionSlug: 'missing-key-first',
             providerType: 'anthropic',
             providerLabel: 'Anthropic',
@@ -58,6 +61,7 @@ describe('model catalog picker helpers', () => {
             thinkingLevels: [],
           },
           {
+            connectionId: 'connection-ready',
             connectionSlug: 'ready-second',
             providerType: 'opencode-free',
             providerLabel: 'OpenCode Zen',
@@ -68,7 +72,11 @@ describe('model catalog picker helpers', () => {
           },
         ],
       }),
-      { llmConnectionSlug: 'ready-second', model: 'ready-model' },
+      {
+        llmConnectionId: 'connection-ready',
+        llmConnectionSlug: 'ready-second',
+        model: 'ready-model',
+      },
     );
   });
   it('keeps API connection labels while redacting OAuth account identities', () => {

apps/desktop/src/main/__tests__/runtime-host-bot-session-adapter.test.ts

@@ -426,6 +426,7 @@ function session(
     hasUnread: false,
     status: 'active',
     backend: 'ai-sdk',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'test-connection',
     connectionLocked: false,
     model: 'test-model',

apps/desktop/src/main/__tests__/runtime-host-client-operations.test.ts

@@ -228,7 +228,7 @@ test('settles revision cleanup when abandon observes an already absent target',
   assert.equal(await client.removeSessionCopy('revision-copy'), 'removed');
 });
 
-test('merges a configuration patch into each fresh CAS projection', async () => {
+test('replays one exact model patch across fresh CAS projections', async () => {
   const { client, requests } = clientWithResponses([
     { kind: 'session', session: session('session-1', 10) },
     { kind: 'revision_conflict', expectedRevision: 10, actualRevision: 11 },
@@ -240,16 +240,22 @@ test('merges a configuration patch into each fresh CAS projection', async () =>
       kind: 'committed',
       session: session('session-1', 12, {
         collaborationMode: 'plan',
-        permissionMode: 'ask',
+        llmConnectionId: 'connection-b',
+        model: 'model-b',
       }),
     },
   ]);
 
   const updated = await client.updateSessionConfiguration('session-1', {
-    permissionMode: 'ask',
+    modelTarget: {
+      kind: 'explicit',
+      connectionId: 'connection-b',
+      connectionSlug: 'test-connection',
+      model: 'model-b',
+    },
   });
 
-  assert.equal(updated.permissionMode, 'ask');
+  assert.equal(updated.llmConnectionId, 'connection-b');
   assert.equal(updated.collaborationMode, 'plan');
   assert.deepEqual(
     requests
@@ -259,31 +265,25 @@ test('merges a configuration patch into each fresh CAS projection', async () =>
       {
         sessionId: 'session-1',
         expectedRevision: 10,
-        configuration: {
+        patch: {
           modelTarget: {
             kind: 'explicit',
+            connectionId: 'connection-b',
             connectionSlug: 'test-connection',
-            model: 'test-model',
+            model: 'model-b',
           },
-          thinkingLevel: null,
-          permissionMode: 'ask',
-          collaborationMode: 'agent',
-          orchestrationMode: 'default',
         },
       },
       {
         sessionId: 'session-1',
         expectedRevision: 11,
-        configuration: {
+        patch: {
           modelTarget: {
             kind: 'explicit',
+            connectionId: 'connection-b',
             connectionSlug: 'test-connection',
-            model: 'test-model',
+            model: 'model-b',
           },
-          thinkingLevel: null,
-          permissionMode: 'ask',
-          collaborationMode: 'plan',
-          orchestrationMode: 'default',
         },
       },
     ],
@@ -1002,6 +1002,7 @@ function session(
     hasUnread: false,
     status: 'active',
     backend: 'ai-sdk',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'test-connection',
     connectionLocked: true,
     model: 'test-model',

apps/desktop/src/main/__tests__/runtime-host-client-uds.test.ts

@@ -175,15 +175,22 @@ test('drives the renderer Session catalog facade through real UDS framing', asyn
           'session.configuration.update': async (input) => {
             assert.ok(projected);
             assert.equal(input.expectedRevision, projected.revision);
+            const { thinkingLevel: _thinkingLevel, ...withoutThinkingLevel } = projected;
             projected = session(projected.id, {
-              ...projected,
+              ...(input.patch.thinkingLevel === null ? withoutThinkingLevel : projected),
               revision: projected.revision + 1,
-              permissionMode: input.configuration.permissionMode,
-              collaborationMode: input.configuration.collaborationMode,
-              orchestrationMode: input.configuration.orchestrationMode,
-              ...(input.configuration.thinkingLevel === null
+              ...(input.patch.permissionMode === undefined
+                ? {}
+                : { permissionMode: input.patch.permissionMode }),
+              ...(input.patch.collaborationMode === undefined
+                ? {}
+                : { collaborationMode: input.patch.collaborationMode }),
+              ...(input.patch.orchestrationMode === undefined
+                ? {}
+                : { orchestrationMode: input.patch.orchestrationMode }),
+              ...(input.patch.thinkingLevel === null || input.patch.thinkingLevel === undefined
                 ? {}
-                : { thinkingLevel: input.configuration.thinkingLevel }),
+                : { thinkingLevel: input.patch.thinkingLevel }),
             });
             return { ok: true, result: { kind: 'committed', session: projected } };
           },
@@ -610,6 +617,7 @@ function session(
     hasUnread: false,
     status: 'active',
     backend: 'ai-sdk',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'test-connection',
     connectionLocked: true,
     model: 'test-model',

apps/desktop/src/main/__tests__/runtime-host-desktop-candidate.test.ts

@@ -1240,6 +1240,7 @@ function session(id: string): SessionCatalogProjection {
     hasUnread: false,
     status: 'active',
     backend: 'ai-sdk',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'test-connection',
     connectionLocked: true,
     model: 'test-model',

apps/desktop/src/main/__tests__/runtime-host-external-sessions-ipc-main.test.ts

@@ -214,6 +214,7 @@ function session(id: string): SessionCatalogProjection {
     hasUnread: false,
     status: 'active',
     backend: 'ai-sdk',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'default',
     connectionLocked: true,
     model: 'gpt-5',

apps/desktop/src/main/__tests__/runtime-host-search-ipc-main.test.ts

@@ -171,6 +171,7 @@ function catalogSession(id: string, name: string): SessionCatalogProjection {
     hasUnread: false,
     status: 'active',
     backend: 'ai-sdk',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'zai-live',
     connectionLocked: true,
     model: 'glm-5.1',

apps/desktop/src/main/__tests__/runtime-host-session-catalog-ipc-main.test.ts

@@ -54,6 +54,7 @@ function projection(overrides: Partial<SessionCatalogProjection> = {}): SessionC
     hasUnread: false,
     status: 'active',
     backend: 'ai-sdk',
+    llmConnectionId: 'connection-1',
     llmConnectionSlug: 'openai-main',
     connectionLocked: true,
     model: 'gpt-5',

apps/desktop/src/main/__tests__/runtime-host-session-catalog-running-turns.test.ts

@@ -116,6 +116,7 @@ function session(id: string): SessionCatalogProjection {
     hasUnread: false,
     status: 'active',
     backend: 'fake',
+    llmConnectionId: null,
     llmConnectionSlug: 'fake',
     connectionLocked: true,
     model: 'fake-model',

apps/desktop/src/main/__tests__/runtime-host-session-execution-ipc-main.test.ts

@@ -1557,6 +1557,7 @@ function session(cwd = "/workspace", id = 'session-1'): SessionCatalogProjection
     hasUnread: false,
     status: "active",
     backend: "ai-sdk",
+    llmConnectionId: "connection-1",
     llmConnectionSlug: "test-connection",
     connectionLocked: true,
     model: "test-model",

apps/desktop/src/main/__tests__/stale-sessions.test.ts

@@ -40,9 +40,9 @@ test('derives stale rows from each Session Host readiness projection', () => {
           connectionLocked: true,
         },
         'remote-rebind': {
-          kind: 'rebind',
-          connectionSlug: 'replacement',
-          model: 'model',
+          kind: 'blocked',
+          reason: 'connection_missing',
+          connectionLocked: false,
         },
         // #3211: a retired backend reaches the rail as a projection reason like
         // any other. The row is no longer identified by reading its `backend`.
@@ -53,7 +53,7 @@ test('derives stale rows from each Session Host readiness projection', () => {
         },
       },
     })],
-    ['remote-missing', 'legacy-fake'],
+    ['remote-missing', 'remote-rebind', 'legacy-fake'],
   );
 });
 

apps/desktop/src/main/__tests__/task-readiness-notice.test.ts

@@ -26,14 +26,14 @@ import {
   resolveTaskReadinessModelTarget,
 } from '../../renderer/task-readiness-notice.js';
 
-test('an unlocked stale session checks the send projection rebind target', () => {
+test('an unlocked stale session keeps its stored target until explicit recovery', () => {
   assert.deepEqual(
     resolveTaskReadinessModelTarget(
       { llmConnectionSlug: 'stale', model: 'removed-model' },
-      { kind: 'rebind', connectionSlug: 'healthy', model: 'ready-model' },
+      { kind: 'blocked', reason: 'connection_missing', connectionLocked: false },
       undefined,
     ),
-    { connectionSlug: 'healthy', model: 'ready-model' },
+    { connectionSlug: 'stale', model: 'removed-model' },
   );
 });
 

apps/desktop/src/main/onboarding-service.ts

@@ -60,7 +60,7 @@ import { projectSessionSendOutcome, type SessionSendProjection } from '@maka/cor
 
 import { type SessionSummary } from '@maka/core/session';
 import { buildChatModelChoices, type ChatModelChoice } from '@maka/core/chat-model-choice';
-import type { LlmConnection } from '@maka/core/llm-connections';
+import type { IdentifiedLlmConnection, LlmConnection } from '@maka/core/llm-connections';
 
 export interface OnboardingSnapshot {
   state: OnboardingState;
@@ -71,14 +71,14 @@ export interface OnboardingSnapshot {
    */
   sessions: SessionSummary[];
   /** Default Host connection projection used to seed the shell. */
-  connections: LlmConnection[];
+  connections: IdentifiedLlmConnection[];
   defaultSlug: string | null;
   chatModelChoices: ChatModelChoice[];
   sessionSendOutcomes: Record<string, SessionSendProjection>;
 }
 
 export interface OnboardingServiceDeps {
-  listConnections(): Promise<LlmConnection[]>;
+  listConnections(): Promise<IdentifiedLlmConnection[]>;
   getDefaultSlug(): Promise<string | null>;
   listSessions(): Promise<SessionSummary[]>;
   getMilestones(): Promise<OnboardingMilestone[]>;
@@ -196,7 +196,7 @@ function buildSnapshot(
   state: OnboardingState,
   milestones: OnboardingMilestone[],
   sessions: SessionSummary[],
-  connections: LlmConnection[],
+  connections: IdentifiedLlmConnection[],
   defaultSlug: string | null,
   secrets: Readonly<Record<string, boolean>>,
 ): OnboardingSnapshot {
@@ -213,7 +213,6 @@ function buildSnapshot(
         projectSessionSendOutcome({
           session,
           connections,
-          defaultSlug,
           hasSecret: (slug) => secrets[slug] ?? false,
         }),
       ]),