docs: update script usage paths in documentation

Update internal documentation in migration scripts to reflect
new paths in scripts/ directory instead of automation/scripts/.

Author: claude

scripts/backfill_review_metadata.py

@@ -11,8 +11,8 @@
 always takes the LAST one (the one that led to merge).
 
 Usage:
-    python automation/scripts/backfill_review_metadata.py --dry-run
-    python automation/scripts/backfill_review_metadata.py --execute
+    python scripts/backfill_review_metadata.py --dry-run
+    python scripts/backfill_review_metadata.py --execute
 
 Requires:
     - gh CLI authenticated

scripts/migrate_metadata_format.py

@@ -7,7 +7,7 @@
 2. metadata/{library}.yaml: Flatten current:, remove history, add created/updated/review
 3. implementations/*.py: Update docstring header to new format
 
-Run: uv run python automation/scripts/migrate_metadata_format.py
+Run: uv run python scripts/migrate_metadata_format.py
 """
 
 import re

scripts/migrate_to_new_structure.py

@@ -12,7 +12,7 @@
 - metadata/{library}.yaml (per-library: preview_url, current, history)
 
 Usage:
-    python automation/scripts/migrate_to_new_structure.py [--dry-run]
+    python scripts/migrate_to_new_structure.py [--dry-run]
 """
 
 import argparse