feat: add gateway TUI

src/tui/layout.ts

@@ -0,0 +1,40 @@
+import type { Component } from "@mariozechner/pi-tui";
+
+export class ChatLayout implements Component {
+  constructor(
+    private header: Component,
+    private messages: Component,
+    private status: Component,
+    private input: Component,
+  ) {}
+
+  invalidate(): void {
+    this.header.invalidate?.();
+    this.messages.invalidate?.();
+    this.status.invalidate?.();
+    this.input.invalidate?.();
+  }
+
+  render(width: number): string[] {
+    const rows = process.stdout.rows ?? 24;
+    const headerLines = this.header.render(width);
+    const statusLines = this.status.render(width);
+    const inputLines = this.input.render(width);
+
+    const reserved = headerLines.length + statusLines.length + inputLines.length;
+    const available = Math.max(rows - reserved, 0);
+
+    const messageLines = this.messages.render(width);
+    const slicedMessages =
+      available > 0
+        ? messageLines.slice(Math.max(0, messageLines.length - available))
+        : [];
+
+    const lines = [...headerLines, ...slicedMessages, ...statusLines, ...inputLines];
+    if (lines.length < rows) {
+      const padding = Array.from({ length: rows - lines.length }, () => "");
+      return [...lines, ...padding];
+    }
+    return lines.slice(0, rows);
+  }
+}