test: add coverage for orchestrator + gitea client (diff gate 77% → 98%)

Three new unit test modules:
- tests/unit/test_contrib_gitea_client.py — GiteaClient (urllib mocked)
  and GiteaForge delegation
- tests/unit/orchestrator/test_main.py — __main__ run/status commands
- tests/unit/orchestrator/test_bootstrap.py — _token, BotBottleStateStore,
  _to_forge_state/_to_record, make_forge, make_sidecar, build

Augments to existing suites:
- test_events: non-"created" comment action ignored
- test_lifecycle: _iso_now callable, untracked-issue comment ignored,
  untracked-PR closed ignored (covers _find_by_pr return-None path)
- test_runner: destroy command, _default_run via subprocess mock
- test_sidecar: _jsonable dataclass/list branches, OpLog.read on missing
  file, drain_done_events on corrupted file, socket _Handler invalid-JSON
  and empty-line paths, serve() with pre-existing socket path
- test_watchdog: _loop body covered by patching _TICK_SECS to 0.01s
- test_webhook: unknown GET path returns 404

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

tests/unit/orchestrator/test_lifecycle.py

@@ -135,6 +135,29 @@ class LifecycleTest(unittest.TestCase):
         self.assertIn(("destroy", "impl-didericis-bot-bottle-17"), self.runner.calls)
         self.assertIsNone(self._record())
 
+    def test_comment_on_untracked_issue_ignored(self):
+        # No record in store and is_pull=False -> _route_comment returns None.
+        self.orch.handle(CommentCreated(
+            owner="didericis", repo="bot-bottle", issue_number=99,
+            comment_id=1, author="reviewer", body="hi", is_pull=False,
+        ))
+        self.assertEqual([], self.runner.calls)
+
+    def test_pr_closed_untracked_pr_ignored(self):
+        # _find_by_pr finds nothing -> _on_pr_closed exits early.
+        self.orch.handle(PullRequestClosed(
+            owner="didericis", repo="bot-bottle", pr_number=999, merged=True,
+        ))
+        self.assertEqual([], self.runner.calls)
+
+
+class IsoNowTest(unittest.TestCase):
+    def test_returns_iso_string(self):
+        from bot_bottle.orchestrator.lifecycle import _iso_now
+        ts = _iso_now()
+        self.assertIsInstance(ts, str)
+        self.assertIn("T", ts)
+
 
 if __name__ == "__main__":
     unittest.main()