chore: add repository metadata required for npm provenance

npm's provenance verification rejects publishes when package.json's
repository.url doesn't match the GitHub repo URL from the OIDC claim.
Add repository, bugs, and homepage pointing at tepeumut/agentpull.

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

Author: tepeumut

package.json

@@ -13,6 +13,14 @@
     "cli"
   ],
   "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/tepeumut/agentpull.git"
+  },
+  "bugs": {
+    "url": "https://github.com/tepeumut/agentpull/issues"
+  },
+  "homepage": "https://github.com/tepeumut/agentpull#readme",
   "type": "module",
   "engines": {
     "node": ">=20.0.0"