fix: Add updated_at column back to ELABDATADISP table

The updated_at column was removed from the schema but should be kept for
consistency with the original table structure and to track when rows are
modified.

Changes:
- Added updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP to table schema
- Added updated_at to get_column_order() for elabdatadisp
- Added updated_at to transform_elabdatadisp_row() output

This maintains backward compatibility while still consolidating node_num,
state, and calc_err into the measurements JSONB.

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

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/transformers/schema_transformer.py

@@ -89,7 +89,8 @@ CREATE TABLE IF NOT EXISTS elabdatadisp (
     tool_name_id VARCHAR(32) NOT NULL,
     event_timestamp TIMESTAMP NOT NULL,
     measurements JSONB,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
 ) PARTITION BY RANGE (EXTRACT(YEAR FROM event_timestamp));
 
 -- Note: PostgreSQL doesn't support PRIMARY KEY or UNIQUE constraints