fix: resolve multiple production issues

- Fix archive page showing "00" instead of "0" for empty photo counts
- Fix email queue PostgreSQL "updated_at" column error with migration and fallback
- Fix storage calculation discrepancies between system status and archive pages
- Add proper storage info to system status endpoint
- Fix archive path concatenation in settings endpoint

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

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

backend/migrations/025_fix_email_queue_updated_at.js

@@ -0,0 +1,33 @@
+/**
+ * Fix email_queue table by ensuring it doesn't have updated_at column
+ * This migration addresses the PostgreSQL error where queries are trying to update
+ * a non-existent updated_at column
+ */
+
+exports.up = async function(knex) {
+  // First, check if the column exists
+  const hasUpdatedAt = await knex.schema.hasColumn('email_queue', 'updated_at');
+  
+  if (hasUpdatedAt) {
+    console.log('Found updated_at column in email_queue table, removing it...');
+    await knex.schema.table('email_queue', (table) => {
+      table.dropColumn('updated_at');
+    });
+  }
+  
+  // Also ensure the table has all required columns
+  const hasCreatedAt = await knex.schema.hasColumn('email_queue', 'created_at');
+  if (!hasCreatedAt) {
+    console.log('Adding missing created_at column to email_queue table...');
+    await knex.schema.table('email_queue', (table) => {
+      table.datetime('created_at').defaultTo(knex.fn.now());
+    });
+  }
+  
+  console.log('email_queue table schema fixed');
+};
+
+exports.down = async function(knex) {
+  // In the down migration, we don't add back updated_at since it shouldn't exist
+  // This is intentionally left minimal
+};