feat: refine ISAC media and notification workflows

database/schema.sql

@@ -1081,9 +1081,14 @@ CREATE TABLE IF NOT EXISTS managed_images (
 	byte_size INTEGER NOT NULL CHECK(byte_size > 0),
 	width INTEGER NOT NULL CHECK(width > 0),
 	height INTEGER NOT NULL CHECK(height > 0),
+	source_entity_type TEXT,
+	source_entity_id TEXT,
 	created_by TEXT NOT NULL REFERENCES users(id),
 	created_at TEXT NOT NULL,
 	updated_at TEXT NOT NULL
 );
 CREATE UNIQUE INDEX IF NOT EXISTS managed_images_name_nocase_idx ON managed_images(name COLLATE NOCASE);
 CREATE INDEX IF NOT EXISTS managed_images_category_idx ON managed_images(category);
+CREATE UNIQUE INDEX IF NOT EXISTS managed_images_source_entity_idx
+	ON managed_images(source_entity_type,source_entity_id)
+	WHERE source_entity_type IS NOT NULL AND source_entity_id IS NOT NULL;