fix: resolve database migration failures and startup ordering

- Add scripts/run-migrations.js to run migrations before data loading
- Fix startup.sh ordering: migrations -> data load -> app start
- Fix migration 0005 missing statement-breakpoint between ALTER TABLE statements
- Add migration 0005 to drizzle journal (was missing)
- Fix load-initial-data.js to check table existence before querying
- Fix load-initial-data.js to create chart record before inserting candles (chart_id NOT NULL constraint)
- Simplify db/index.ts migration error handling (remove overly broad 'already exists' catch)
- Add pre-migration check for inconsistent DB state (tables without migration tracking)

drizzle/0005_add_source_and_model_prediction_to_span_annotations.sql

@@ -4,7 +4,7 @@
 -- Add source field (defaults to 'human')
 -- Possible values: 'human', 'model', 'human_correction'
 ALTER TABLE `span_annotations` ADD COLUMN `source` TEXT NOT NULL DEFAULT 'human';
-
+--> statement-breakpoint
 -- Add model_prediction field (nullable JSON)
 -- Stores model prediction metadata when user confirms/corrects a prediction
 -- Example: {"label": "bull_flag", "confidence": 0.85, "model_version": "xgb_v1"}

drizzle/meta/_journal.json

@@ -36,6 +36,13 @@
       "when": 1771055000000,
       "tag": "0004_add_default_span_label_types",
       "breakpoints": true
+    },
+    {
+      "idx": 5,
+      "version": "6",
+      "when": 1771156000000,
+      "tag": "0005_add_source_and_model_prediction_to_span_annotations",
+      "breakpoints": true
     }
   ]
 }