Prevent issue watcher overwrites across colliding repo slugs

lib/clauck

@@ -3738,6 +3738,7 @@ After each check, write current state to `~/.clauck/.state/<job-name>.json`:
 
 def _install_issue_watcher(issue_url: str, notify_channel: str = "") -> str:
     """Install a watcher job for a GitHub issue. Returns the job name."""
+    import hashlib
     import re as _re
 
     m = _re.search(r"github\.com/([^/]+/[^/]+)/issues/(\d+)", issue_url)
@@ -3747,7 +3748,8 @@ def _install_issue_watcher(issue_url: str, notify_channel: str = "") -> str:
     number = m.group(2)
 
     slug = _re.sub(r"[^a-z0-9]+", "-", repo.lower()).strip("-")
-    job_name = f"gh-watch-{slug}-{number}"
+    repo_hash = hashlib.sha1(repo.lower().encode("utf-8")).hexdigest()[:8]
+    job_name = f"gh-watch-{slug}-{number}-{repo_hash}"
     job_path = JOBS_DIR / f"{job_name}.md"
 
     notify_default = notify_channel or ""

tests/test_clauck_report.py

@@ -182,13 +182,31 @@ def test_job_name_contains_issue_number(self):
         name = _install_issue_watcher(url)
         self.assertIn("99", name)
 
+    def test_same_repo_keeps_stable_name(self):
+        url = "https://github.com/acme/widget/issues/42"
+        self.assertEqual(_install_issue_watcher(url), _install_issue_watcher(url))
+
     def test_job_file_contains_issue_url(self):
         url = "https://github.com/acme/widget/issues/7"
         name = _install_issue_watcher(url)
         job = Path(self.tmp.name) / f"{name}.md"
         content = job.read_text()
         self.assertIn(url, content)
 
+    def test_repo_hash_prevents_dash_slash_collision(self):
+        left = _install_issue_watcher("https://github.com/acme/x-y/issues/42")
+        right = _install_issue_watcher("https://github.com/acme-x/y/issues/42")
+        self.assertNotEqual(left, right)
+        self.assertTrue((Path(self.tmp.name) / f"{left}.md").exists())
+        self.assertTrue((Path(self.tmp.name) / f"{right}.md").exists())
+
+    def test_repo_hash_prevents_dot_collision(self):
+        left = _install_issue_watcher("https://github.com/acme/re.po/issues/42")
+        right = _install_issue_watcher("https://github.com/acme-re/po/issues/42")
+        self.assertNotEqual(left, right)
+        self.assertTrue((Path(self.tmp.name) / f"{left}.md").exists())
+        self.assertTrue((Path(self.tmp.name) / f"{right}.md").exists())
+
     def test_job_file_has_valid_cron(self):
         url = "https://github.com/acme/widget/issues/7"
         name = _install_issue_watcher(url)