fix(tui): align resolveModelSelection priority with gateway

Reorder conditions in resolveModelSelection so that modelOverride is
checked before runtime model/modelProvider, matching the priority in
resolveSessionModelRef (session-utils.ts).

Without this change, a session with both a runtime model (from a
previous run) and a modelOverride (from /model) would display the
stale runtime model in the footer instead of the user's selection.

Add a test case covering override precedence over runtime model.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/tui/tui-session-actions.test.ts

@@ -331,4 +331,69 @@ describe("tui session actions", () => {
     expect(state.sessionInfo.modelProvider).toBe("my-copilot");
     expect(state.sessionInfo.contextTokens).toBe(200000);
   });
+
+  it("prefers modelOverride over runtime model in session entry", async () => {
+    // After /model switch, the entry has both a runtime model (from last run)
+    // and a modelOverride (user's intent for next run). The override should win.
+    const listSessions = vi.fn().mockResolvedValue({
+      ts: Date.now(),
+      path: "/tmp/sessions.json",
+      count: 1,
+      defaults: {},
+      sessions: [
+        {
+          key: "agent:main:main",
+          model: "gpt-5.3-codex",
+          modelProvider: "openai-codex",
+          modelOverride: "claude-opus-4-6",
+          providerOverride: "anthropic",
+          updatedAt: 200,
+        },
+      ],
+    });
+
+    const state: TuiStateAccess = {
+      agentDefaultId: "main",
+      sessionMainKey: "agent:main:main",
+      sessionScope: "global",
+      agents: [],
+      currentAgentId: "main",
+      currentSessionKey: "agent:main:main",
+      currentSessionId: null,
+      activeChatRunId: null,
+      historyLoaded: false,
+      sessionInfo: {},
+      initialSessionApplied: true,
+      isConnected: true,
+      autoMessageSent: false,
+      toolsExpanded: false,
+      showThinking: false,
+      connectionStatus: "connected",
+      activityStatus: "idle",
+      statusTimeout: null,
+      lastCtrlCAt: 0,
+    };
+
+    const { refreshSessionInfo } = createSessionActions({
+      client: { listSessions } as unknown as GatewayChatClient,
+      chatLog: { addSystem: vi.fn() } as unknown as import("./components/chat-log.js").ChatLog,
+      tui: { requestRender: vi.fn() } as unknown as import("@mariozechner/pi-tui").TUI,
+      opts: {},
+      state,
+      agentNames: new Map(),
+      initialSessionInput: "",
+      initialSessionAgentId: null,
+      resolveSessionKey: vi.fn(),
+      updateHeader: vi.fn(),
+      updateFooter: vi.fn(),
+      updateAutocompleteProvider: vi.fn(),
+      setActivityStatus: vi.fn(),
+    });
+
+    await refreshSessionInfo();
+
+    // Override should take precedence over runtime model
+    expect(state.sessionInfo.model).toBe("claude-opus-4-6");
+    expect(state.sessionInfo.modelProvider).toBe("anthropic");
+  });
 });

src/tui/tui-session-actions.ts

@@ -118,17 +118,21 @@ export function createSessionActions(context: SessionActionContext) {
     entry?: SessionInfoEntry,
     defaults?: SessionInfoDefaults | null,
   ) => {
+    // 1. Explicit user override (set via /model) wins over last-run runtime model.
+    //    This matches the priority in resolveSessionModelRef (session-utils.ts).
+    const overrideModel = entry?.modelOverride?.trim();
+    if (overrideModel) {
+      const overrideProvider = entry?.providerOverride?.trim() || state.sessionInfo.modelProvider;
+      return { modelProvider: overrideProvider, model: overrideModel };
+    }
+    // 2. Fall back to runtime model from last run.
     if (entry?.modelProvider || entry?.model) {
       return {
         modelProvider: entry.modelProvider ?? state.sessionInfo.modelProvider,
         model: entry.model ?? state.sessionInfo.model,
       };
     }
-    const overrideModel = entry?.modelOverride?.trim();
-    if (overrideModel) {
-      const overrideProvider = entry?.providerOverride?.trim() || state.sessionInfo.modelProvider;
-      return { modelProvider: overrideProvider, model: overrideModel };
-    }
+    // 3. Configured defaults.
     if (defaults?.modelProvider || defaults?.model) {
       return {
         modelProvider: defaults.modelProvider ?? state.sessionInfo.modelProvider,