Fix SQLMesh config: remove invalid init_script parameter

- Remove init_script from DuckDB connection config (not a valid parameter)
- Move R2 Iceberg catalog initialization to before_all hooks
- Hooks run before sqlmesh plan/run commands
- Uses SQLMesh @env_var() macro syntax for environment variables

Fixes CI/CD error: 'invalid duckdb connection config: invalid field init_script'

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

transform/sqlmesh_materia/config.yaml

@@ -20,21 +20,28 @@ gateways:
       extensions:
         - name: httpfs
         - name: iceberg
-      init_script: |
-        CREATE SECRET IF NOT EXISTS r2_secret (
-            TYPE ICEBERG,
-            TOKEN '{{ env_var("CLOUDFLARE_API_TOKEN") }}'
-        );
-        ATTACH '{{ env_var("R2_WAREHOUSE_NAME", "materia") }}' AS catalog (
-            TYPE ICEBERG,
-            ENDPOINT '{{ env_var("ICEBERG_REST_URI") }}'
-        );
-        CREATE SCHEMA IF NOT EXISTS catalog.materia;
-        USE catalog.materia;
 
 
 default_gateway: dev
 
+# --- Hooks ---
+# Run initialization SQL before all plans/runs
+# https://sqlmesh.readthedocs.io/en/stable/reference/configuration/#execution-hooks
+
+before_all:
+  - |
+    CREATE SECRET IF NOT EXISTS r2_secret (
+        TYPE ICEBERG,
+        TOKEN '@env_var("CLOUDFLARE_API_TOKEN")'
+    )
+  - |
+    ATTACH '@env_var("R2_WAREHOUSE_NAME", "materia")' AS catalog (
+        TYPE ICEBERG,
+        ENDPOINT '@env_var("ICEBERG_REST_URI")'
+    )
+  - CREATE SCHEMA IF NOT EXISTS catalog.materia
+  - USE catalog.materia
+
 # --- Model Defaults ---
 # https://sqlmesh.readthedocs.io/en/stable/reference/model_configuration/#model-defaults