Add update_incoming_fks parameter to transform()

When renaming columns that are referenced by foreign keys in other
tables, the transform() method now accepts update_incoming_fks=True
to automatically update those FK constraints.

Implementation:
- Added _get_incoming_fks_needing_update() helper to find tables
  with FKs pointing to renamed columns
- Modified transform() to collect SQL for updating incoming FKs
- Execute main transform first (so new column exists), then update
  incoming FKs, all within the same transaction
- Added _skip_fk_validation flag to allow generating SQL for FKs
  that reference columns that don't exist yet (will exist after
  main transform completes)

Includes test for basic column rename case with FK enforcement ON.

tests/test_transform.py

@@ -661,3 +661,50 @@ def test_transform_with_unique_constraint_implicit_index(fresh_db):
         "You must manually drop this index prior to running this transformation and manually recreate the new index after running this transformation."
         in str(excinfo.value)
     )
+
+
+def test_transform_update_incoming_fks_on_column_rename(fresh_db):
+    """
+    Test that update_incoming_fks=True updates FK constraints in other tables
+    when a referenced column is renamed.
+    """
+    fresh_db.execute("PRAGMA foreign_keys=ON")
+
+    # Create authors table with id as PK
+    fresh_db["authors"].insert({"id": 1, "name": "Alice"}, pk="id")
+
+    # Create books table with FK to authors.id
+    fresh_db["books"].insert(
+        {"id": 1, "title": "Book A", "author_id": 1},
+        pk="id",
+        foreign_keys=[("author_id", "authors", "id")],
+    )
+
+    # Verify initial FK
+    assert fresh_db["books"].foreign_keys == [
+        ForeignKey(table="books", column="author_id", other_table="authors", other_column="id")
+    ]
+
+    # Rename authors.id to authors.author_pk with update_incoming_fks=True
+    fresh_db["authors"].transform(
+        rename={"id": "author_pk"},
+        update_incoming_fks=True,
+    )
+
+    # Verify authors column was renamed
+    assert "author_pk" in fresh_db["authors"].columns_dict
+    assert "id" not in fresh_db["authors"].columns_dict
+
+    # Verify books FK was updated to point to new column name
+    assert fresh_db["books"].foreign_keys == [
+        ForeignKey(table="books", column="author_id", other_table="authors", other_column="author_pk")
+    ]
+
+    # Verify data integrity
+    assert list(fresh_db["authors"].rows) == [{"author_pk": 1, "name": "Alice"}]
+    assert list(fresh_db["books"].rows) == [{"id": 1, "title": "Book A", "author_id": 1}]
+
+    # Verify FK enforcement still works
+    assert fresh_db.execute("PRAGMA foreign_keys").fetchone()[0] == 1
+    violations = list(fresh_db.execute("PRAGMA foreign_key_check").fetchall())
+    assert violations == []