feat(ui): add dedicated TUI package

Move the interactive pi-tui front door into @deepseek-ai/dsh-tui while keeping @deepseek-ai/dsh-stdio line-oriented for pipes. Select the terminal package in the demo app, preserve logger ownership, and cover the production Loader composition with a PTY smoke test.

packages/ui/tui/tsconfig.json

@@ -0,0 +1,33 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../../../vendor/schemastery"
+    },
+    {
+      "path": "../../core/agent"
+    },
+    {
+      "path": "../../core/session"
+    },
+    {
+      "path": "../../llm/llm"
+    },
+    {
+      "path": "../../core/tools"
+    },
+    {
+      "path": "../user-interaction"
+    }
+  ]
+}