fix(cli): switched model command to session selector

- Routed the TUI /model command through the temporary session model selector used by /switch and Alt+P.
- Added slash-command coverage for /model opening the session selector.

Fixes #2846

packages/coding-agent/CHANGELOG.md

@@ -22,6 +22,7 @@
 
 ### Fixed
 
+- Fixed `/model` in the TUI to open the active-session model switcher instead of the role-assignment picker ([#2846](https://github.com/can1357/oh-my-pi/issues/2846)).
 - Fixed Whisper STT cache detection to require both encoder and decoder `.onnx` files, so partial model downloads now trigger a proper foreground download instead of being treated as fully cached
 - Fixed same-process `JsRuntime` cleanup so disposing an older inline/direct runtime no longer deletes a newer runtime's JS helper globals; inactive cmux/direct runtimes now re-activate their globals before sequential use while overlapping cross-runtime runs fail explicitly.
 - Fixed magic-keyword steering notices (`ultrathink-notice`, `orchestrate-notice`, `workflow-notice`) to be prepended before the related user message so they influence that same turn

packages/coding-agent/src/slash-commands/builtin-registry.ts

@@ -308,7 +308,7 @@ const BUILTIN_SLASH_COMMAND_REGISTRY: ReadonlyArray<SlashCommandSpec> = [
 	{
 		name: "model",
 		aliases: ["models"],
-		description: "Select model (opens selector UI)",
+		description: "Switch model for this session",
 		acpDescription: "Show current model selection",
 		handle: async (command, runtime) => {
 			if (command.args) {
@@ -341,7 +341,7 @@ const BUILTIN_SLASH_COMMAND_REGISTRY: ReadonlyArray<SlashCommandSpec> = [
 			return commandConsumed();
 		},
 		handleTui: (_command, runtime) => {
-			runtime.ctx.showModelSelector();
+			runtime.ctx.showModelSelector({ temporaryOnly: true });
 			runtime.ctx.editor.setText("");
 		},
 	},

packages/coding-agent/test/slash-commands/switch.test.ts

@@ -17,6 +17,18 @@ function createRuntime() {
 	};
 }
 
+describe("/model slash command", () => {
+	it("opens the temporary model selector for the active session", async () => {
+		const harness = createRuntime();
+
+		const handled = await executeBuiltinSlashCommand("/model", harness.runtime);
+
+		expect(handled).toBe(true);
+		expect(harness.showModelSelector).toHaveBeenCalledWith({ temporaryOnly: true });
+		expect(harness.setText).toHaveBeenCalledWith("");
+	});
+});
+
 describe("/switch slash command", () => {
 	it("opens the temporary model selector (mirrors alt+p)", async () => {
 		const harness = createRuntime();