feat: add /api/system/version endpoint with changelog

Mengembalikan versi aplikasi, git commit hash, branch aktif, dan 20 commit terakhir untuk memverifikasi apakah staging/production sudah terupdate.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app.ts

@@ -1010,6 +1010,39 @@ export function createApp() {
         tags: ['System'],
       },
     })
+    .get('/api/system/version', async () => {
+      const pkg = await Bun.file('./package.json').json()
+      let commit = 'unknown'
+      let branch = 'unknown'
+      let changelog: { hash: string; date: string; author: string; message: string }[] = []
+      try {
+        const commitProc = Bun.spawn(['git', 'rev-parse', '--short', 'HEAD'], { stdout: 'pipe', stderr: 'pipe' })
+        commit = (await new Response(commitProc.stdout).text()).trim()
+        const branchProc = Bun.spawn(['git', 'rev-parse', '--abbrev-ref', 'HEAD'], { stdout: 'pipe', stderr: 'pipe' })
+        branch = (await new Response(branchProc.stdout).text()).trim()
+        const logProc = Bun.spawn(
+          ['git', 'log', '--pretty=format:%h|%aI|%an|%s', '-20'],
+          { stdout: 'pipe', stderr: 'pipe' },
+        )
+        const logText = (await new Response(logProc.stdout).text()).trim()
+        changelog = logText.split('\n').filter(Boolean).map(line => {
+          const [hash, date, author, ...msgParts] = line.split('|')
+          return { hash, date, author, message: msgParts.join('|') }
+        })
+      } catch { /* git not available */ }
+      return {
+        version: pkg.version as string,
+        commit,
+        branch,
+        changelog,
+      }
+    }, {
+      detail: {
+        summary: 'Version Info',
+        description: 'Mengembalikan versi aplikasi, git commit hash, branch aktif, dan 20 commit terakhir sebagai changelog.',
+        tags: ['System'],
+      },
+    })
 
     // ─── Example API ───────────────────────────────────
     .get('/api/hello', () => ({