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/tests/unit/health.test.ts

@@ -0,0 +1,24 @@
+import { describe, it, expect } from "vitest";
+import { runAllChecks, runCheck } from "~/services/health/facade.js";
+
+describe("health checks", () => {
+  it("runAllChecks returns 6 results", () => {
+    const results = runAllChecks();
+    expect(results).toHaveLength(6);
+    for (const r of results) {
+      expect(r).toHaveProperty("name");
+      expect(r).toHaveProperty("ok");
+      expect(r).toHaveProperty("message");
+    }
+  });
+
+  it("node-version passes on Node 20+", () => {
+    const result = runCheck("node-version");
+    expect(result).not.toBeNull();
+    expect(result!.ok).toBe(true);
+  });
+
+  it("runCheck returns null for unknown check", () => {
+    expect(runCheck("nonexistent")).toBeNull();
+  });
+});