refactor(examples): give TUI its own agent leaf

examples/tui-agent/cordis.yml

@@ -0,0 +1,28 @@
+# Full-screen TUI front door over the same coding-agent composition used by the
+# readline REPL. The include keeps backends and optional tools aligned; the
+# patch owns only the terminal-specific app config.
+- id: base
+  name: '@cordisjs/plugin-include'
+  config:
+    path: ../coding-agent/cordis.yml
+    patches:
+      - id: stdio-agent
+        name: '@deepseek-ai/dsh-stdio-demo'
+        config:
+          provider: deepseek
+          model: deepseek-v4-flash
+          resumeSessionId: !!js process.env.RESUME_SESSION_ID
+          persistenceRoot: './.sessions'
+          workspaceContext:
+            maxBytes: 65536
+          welcome: 'TUI agent ready. Give it a coding task.'
+          ui:
+            mode: tui
+            tui:
+              showReasoning: true
+              maxToolOutputLines: 12
+          persona: |
+            You are coding-agent, a coding assistant powered by the {{model}} model.
+
+            Verify your work by running the code or tests. Keep answers brief and
+            factual.