feat(KB-131): bundle workspace dependencies into CLI for npm publish

- Replace tsc with tsup (esbuild) to inline @kb/* workspace code into a single dist/bin.js
- Move @kb/core, @kb/dashboard, @kb/engine from dependencies to devDependencies
- Add tsup.config.ts that copies dashboard client assets into dist/client/
- Add bundle output tests verifying shebang, inlined code, and no bare @kb/* imports
- Add changeset for the bundled CLI build fix

packages/cli/tsup.config.ts

@@ -0,0 +1,26 @@
+import { defineConfig } from "tsup";
+import { cpSync, existsSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const dashboardClientSrc = join(__dirname, "..", "dashboard", "dist", "client");
+const dashboardClientDest = join(__dirname, "dist", "client");
+
+export default defineConfig({
+  entry: ["src/bin.ts"],
+  format: ["esm"],
+  platform: "node",
+  target: "node22",
+  noExternal: [/^@kb\//],
+  splitting: false,
+  clean: true,
+  onSuccess: async () => {
+    if (existsSync(dashboardClientSrc)) {
+      cpSync(dashboardClientSrc, dashboardClientDest, { recursive: true });
+      console.log("Copied dashboard client assets to dist/client/");
+    } else {
+      console.warn("WARNING: Dashboard client assets not found at", dashboardClientSrc);
+    }
+  },
+});