feat(database): increase passwordHash length and add migration snapshot

- Extended `passwordHash` field length in `users` schema from 100 to 255.
- Added migration snapshot for schema updates.

backend/.migrations/meta/_journal.json

@@ -64,6 +64,20 @@
       "when": 1769696731978,
       "tag": "0008_bitter_darwin",
       "breakpoints": true
+    },
+    {
+      "idx": 9,
+      "version": "7",
+      "when": 1769717126917,
+      "tag": "0009_add_privacy_settings",
+      "breakpoints": true
+    },
+    {
+      "idx": 10,
+      "version": "7",
+      "when": 1769718997591,
+      "tag": "0010_update_password_hash_length",
+      "breakpoints": true
     }
   ]
 }