chore(docker): remove init-db.sql — database and tables created by tests

The init-db.sql script created a symbol table never used by any test.
The ds_mysql_test database is already created via the MYSQL_DATABASE env var.
Each integration test now creates and drops its own tables via RAII scope_guard.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Pierre-Luc Gagné

tests/integration/docker/docker-compose.yml

@@ -10,7 +10,6 @@ services:
     ports:
       - "${DS_MYSQL_TEST_PORT:-3307}:3306"
     volumes:
-      - ./init-db.sql:/docker-entrypoint-initdb.d/init.sql:ro
       - mysql_data:/var/lib/mysql
     healthcheck:
       test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]

tests/integration/docker/docker_up.sh

@@ -61,14 +61,6 @@ echo "Waiting for MySQL to be ready..."
 for i in {1..60}; do
   if docker-compose -f "$COMPOSE_FILE" exec -T mysql mysqladmin ping -h localhost > /dev/null 2>&1; then
     echo "MySQL is ready"
-
-    # Apply init-db.sql unconditionally so seed data always exists,
-    # even when the data volume was created before changes were added.
-    # The script is idempotent (CREATE TABLE IF NOT EXISTS, INSERT IGNORE).
-    echo "Applying init-db.sql..."
-    docker-compose -f "$COMPOSE_FILE" exec -T mysql \
-      mysql -u root -proot < "$ROOT_DIR/tests/integration/docker/init-db.sql"
-    echo "Database initialisation complete"
     exit 0
   fi
   echo "Waiting... ($i/60)"