feat: Stock Correction Modal (#47)

* feat: add stock correction modal with blister-based input

- Add 'Correct Stock' button to medication detail modal
- New modal with Full Blisters + Partial Blister Pills inputs
- Auto-conversion for edge cases (full/negative partial)
- New stockAdjustment field for DB corrections without touching looseTablets
- New lastStockCorrectionAt timestamp to ignore old consumed doses after correction
- Tracking data preserved for future statistics
- Add Drizzle migrations for new columns
- Add translations for en/de

* fix: add stock_adjustment columns to e2e/integration test schemas

backend/src/db/client.ts

@@ -75,6 +75,10 @@ export async function runAlterMigrations(client: Client): Promise<{ success: boo
     `ALTER TABLE dose_tracking ADD COLUMN dismissed integer NOT NULL DEFAULT 0`,
     // Added in v1.3.x - stock calculation mode (automatic/manual)
     `ALTER TABLE user_settings ADD COLUMN stock_calculation_mode text NOT NULL DEFAULT 'automatic'`,
+    // Added for stock correction - hidden offset that doesn't affect looseTablets
+    `ALTER TABLE medications ADD COLUMN stock_adjustment integer NOT NULL DEFAULT 0`,
+    // Added for stock correction - timestamp to ignore consumed doses before correction
+    `ALTER TABLE medications ADD COLUMN last_stock_correction_at integer`,
   ];
 
   for (const sql of alterMigrations) {