chore(cli-v2): un-ignore CLI source tree for binary release workflow

The CLI source (242 files, ~14k lines) was gitignored during the
earlier cli→cli-v2 reorg so only the published npm package carried it.
That blocks the GitHub Actions release workflow (release-cli.yml),
which clones the repo fresh on each runner and needs the source to
compile binaries via `bun build --compile`.

Moves the gitignore from root-level to `apps/cli-v2/.gitignore` with
only the usual build artefacts excluded (node_modules, dist, .turbo,
.cache). Source is now in git at apps/cli-v2/src/.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/cli-v2/build.ts

@@ -0,0 +1,51 @@
+import { statSync } from "node:fs";
+import { gzipSync } from "node:zlib";
+
+const MAX_GZIPPED_BYTES = 1.2 * 1024 * 1024; // 1.2 MB
+
+const result = await Bun.build({
+  entrypoints: [
+    "src/entrypoints/cli.ts",
+    "src/entrypoints/mcp.ts",
+  ],
+  outdir: "dist/entrypoints",
+  target: "node",
+  format: "esm",
+  splitting: false,
+  sourcemap: "external",
+  external: [
+    "libsodium-wrappers",
+    "ws",
+    "@modelcontextprotocol/sdk",
+  ],
+});
+
+if (!result.success) {
+  console.error("Build failed:");
+  for (const log of result.logs) {
+    console.error(log);
+  }
+  process.exit(1);
+}
+
+for (const output of result.outputs) {
+  const raw = statSync(output.path).size;
+  const gz = gzipSync(await Bun.file(output.path).arrayBuffer()).byteLength;
+  const label = output.path.replace(process.cwd() + "/", "");
+  console.log(`  ${label}  ${(raw / 1024).toFixed(0)} KB  (${(gz / 1024).toFixed(0)} KB gzipped)`);
+
+  if (gz > MAX_GZIPPED_BYTES) {
+    console.error(`\n  ERROR: ${label} exceeds 1.2 MB gzipped ceiling (${(gz / 1024).toFixed(0)} KB)`);
+    process.exit(1);
+  }
+}
+
+const { chmodSync, readFileSync, writeFileSync } = await import("node:fs");
+const cliPath = "dist/entrypoints/cli.js";
+const cliContent = readFileSync(cliPath, "utf-8");
+if (!cliContent.startsWith("#!")) {
+  writeFileSync(cliPath, "#!/usr/bin/env node\n" + cliContent);
+}
+chmodSync(cliPath, 0o755);
+
+console.log("\nBuild complete.");