feat(6243): a directory moved in the tree keeps its shape judgments

Ledger rows are keyed by path, so after a directory moves the next sync
marks every judged row vanished and lists the same shapes again, unjudged.
move_shapes(project_id, from_path, to_path) re-keys the rows under one path
to the other, in every repo of the project, keeping each row's judgment,
uses edges and history and adding a `moved` event that records the path it
left. A row already at the target is replaced when nobody judged it; a
judged one stands, and the old row is reported in `kept`.

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

src/grimoire/mcp/server.py

@@ -200,7 +200,7 @@ _WRITE_TOOLS = frozenset({
     "merge_snippets", "unmerge_snippet",
     "create_process", "update_process", "delete_process",
     "classify_shapes", "classify_shapes_by_rule", "confirm_shape_proposals",
-    "refresh_pattern_coverage",
+    "refresh_pattern_coverage", "move_shapes",
     # design systems
     "create_design_system", "update_design_system", "delete_design_system",
     "create_design_token", "update_design_token", "delete_design_token",