fix(6245): bind_repo(moved_from=…) moves the snippet locations recorded in the old repo

A repo renamed on its forge kept every snippet location naming the old
repo: the binding and the shape ledger moved, the snippets did not.

- snippets.move_location_repo rewrites, on every live snippet of the
  project, each location whose repo is the old remote in any form (URL,
  normalized key, "owner/Repo", bare "Repo", compared without case) to
  the new normalized key. A snippet the caller can only read is listed
  in read_only and left alone.
- Its loop is shared with move_locations through _rewrite_locations,
  which saves each changed snippet through update_snippet.
- bind_repo calls it after the binding moves and reports snippets_moved
  and snippets_read_only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_integration_repo_move.py

@@ -100,3 +100,35 @@ async def test_the_same_repo_under_both_names_is_refused(bound):
         await svc.move_binding(
             bound["owner"], OLD, "git@git.example.com:alice/oldname", bound["pid"],
         )
+
+
+@pytest.mark.integration
+async def test_the_snippets_recorded_in_the_old_repo_move_with_it(bound):
+    from grimoire.services import snippets as snippets_svc
+
+    owner, pid = bound["owner"], bound["pid"]
+
+    async def snippet(name, *repos):
+        note = await snippets_svc.create_snippet(
+            owner, name=name, code=f"def {name}():\n    pass\n", language="python",
+            project_id=pid,
+            locations=[{"repo": r, "path": "src/app.py", "symbol": name} for r in repos],
+        )
+        return int(note.id)
+
+    moved_one = await snippet("moved_one", "OldName", "alice/oldname", OLD)
+    mixed = await snippet("mixed", "git.example.com/alice/oldname", "elsewhere/gadget")
+    untouched = await snippet("untouched", "Gadget", "git.example.com/alice/oldnamesake")
+
+    result = await snippets_svc.move_location_repo(owner, pid, OLD, NEW)
+
+    assert sorted(result["moved"]) == sorted([moved_one, mixed])
+    assert result["read_only"] == []
+
+    async def repos(snippet_id):
+        note = await snippets_svc.get_snippet(owner, snippet_id)
+        return [loc["repo"] for loc in snippets_svc.snippet_fields(note)["locations"]]
+
+    assert await repos(moved_one) == [NEW_KEY, NEW_KEY, NEW_KEY]
+    assert await repos(mixed) == [NEW_KEY, "elsewhere/gadget"]
+    assert await repos(untouched) == ["Gadget", "git.example.com/alice/oldnamesake"]