fix(manifest): normalize is_recovered input through _validate_rel_path

Address Copilot review comment id 4309888722 round-5 (2026-05-21) on PR #2483:

``is_recovered()`` previously checked ``self._recovered_files`` membership
with bare ``Path(rel).as_posix()``, while ``record_existing()`` stores keys
via ``_validate_rel_path(rel, root).relative_to(root).as_posix()``. The two
normalizations disagreed on absolute paths and paths that escape the
project root — ``is_recovered`` would silently return False for inputs that
``record_existing`` would have refused entirely.

The fix routes ``is_recovered`` through the same ``_validate_rel_path``
pipeline; ``ValueError`` from the validator is caught and converted to
False so query semantics stay exception-free (Python ``__contains__``
convention).

Tests: 2 new methods in ``TestManifestRecoveredFiles``:
- ``test_is_recovered_absolute_path_returns_false``
- ``test_is_recovered_escaping_path_returns_false``

🤖 AI disclosure: drafted with assistance from Claude (Opus 4.7).

src/specify_cli/integrations/manifest.py

@@ -222,9 +222,20 @@ class IntegrationManifest:
         return set(self._recovered_files)
 
     def is_recovered(self, rel_path: str | Path) -> bool:
-        """Return True if *rel_path* was recorded via ``record_existing(recovered=True)``."""
-        rel = Path(rel_path)
-        normalized = rel.as_posix()
+        """Return True if *rel_path* was recorded via ``record_existing(recovered=True)``.
+
+        Input is normalized through the same ``_validate_rel_path`` pipeline that
+        ``record_existing`` uses for its stored keys, so the two methods agree
+        on key format. Absolute paths and paths that escape the project root
+        return ``False`` (they cannot match the relative POSIX keys we store) —
+        consistent with Python's membership-predicate convention of not raising
+        on a not-in-set query.
+        """
+        try:
+            abs_path = _validate_rel_path(Path(rel_path), self.project_root)
+            normalized = abs_path.relative_to(self.project_root).as_posix()
+        except ValueError:
+            return False
         return normalized in self._recovered_files
 
     def check_modified(self) -> list[str]: