fix: install sqlite3 in dev container for playwright tests

.devcontainer/Dockerfile

@@ -8,6 +8,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     jq \
     aggregate \
     curl \
+    sqlite3 \
     && rm -rf /var/lib/apt/lists/*
 
 # Install Playwright browser dependencies

frontend/ui-tests/utils/db-cleanup.ts

@@ -25,10 +25,25 @@ export function cleanDatabase(testTempDir: string): void {
         });
         console.log(`[DB Cleanup] Cleared table: ${table}`);
       } catch (error) {
-        console.log(`[DB Cleanup] Skipped ${table} (table may not exist)`);
+        const errorMessage =
+          error instanceof Error ? error.message : String(error);
+
+        // Check if it's a "table doesn't exist" error (expected for new databases)
+        if (errorMessage.includes('no such table')) {
+          console.log(`[DB Cleanup] Skipped ${table} (table does not exist)`);
+        } else {
+          // Unexpected error - this indicates a real problem (e.g., sqlite3 not installed)
+          console.error(
+            `[DB Cleanup] Failed to clear ${table}: ${errorMessage}`
+          );
+          throw new Error(
+            `Database cleanup failed for table ${table}: ${errorMessage}`
+          );
+        }
       }
     }
   } catch (error) {
-    console.warn(`[DB Cleanup] Failed to clean database: ${error}`);
+    console.error(`[DB Cleanup] Fatal error during database cleanup: ${error}`);
+    throw error; // Fail tests immediately if cleanup fails
   }
 }