refactor(api): remove AI worker, add ai api route, add usage tiers

- Remove separate AI worker service
- Added generation limits:
  FREE: 1000/month (For the beta version)
  PRO: 500/month
  ENTERPRISE: 1000/month
- Integrate AI functionality into main API routes
- Added monthly generations reset and usage tier upgrade API routes
- Upgrade tier page to be added along with profile page section

backend/database/drizzle/meta/0000_snapshot.json

@@ -1,7 +1,7 @@
 {
   "version": "5",
   "dialect": "sqlite",
-  "id": "afe10bff-362b-402c-bdb5-038341692f35",
+  "id": "3241d14f-687f-4134-94ab-88bf36e8611e",
   "prevId": "00000000-0000-0000-0000-000000000000",
   "tables": {
     "sandbox": {
@@ -140,13 +140,6 @@
           "autoincrement": false,
           "default": "CURRENT_TIMESTAMP"
         },
-        "image": {
-          "name": "image",
-          "type": "text",
-          "primaryKey": false,
-          "notNull": false,
-          "autoincrement": false
-        },
         "generations": {
           "name": "generations",
           "type": "integer",

backend/database/drizzle/meta/0001_snapshot.json

@@ -1,8 +1,8 @@
 {
   "version": "5",
   "dialect": "sqlite",
-  "id": "e570d5ac-700d-4e62-8a46-482b21ae1fe1",
-  "prevId": "afe10bff-362b-402c-bdb5-038341692f35",
+  "id": "7eafd85c-d63d-43be-aa26-1a0eb2ca1805",
+  "prevId": "3241d14f-687f-4134-94ab-88bf36e8611e",
   "tables": {
     "sandbox": {
       "name": "sandbox",
@@ -147,6 +147,28 @@
           "notNull": false,
           "autoincrement": false,
           "default": 0
+        },
+        "tier": {
+          "name": "tier",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false,
+          "default": "'FREE'"
+        },
+        "tierExpiresAt": {
+          "name": "tierExpiresAt",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "lastResetDate": {
+          "name": "lastResetDate",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
         }
       },
       "indexes": {

backend/database/drizzle/meta/_journal.json

@@ -5,29 +5,15 @@
     {
       "idx": 0,
       "version": "5",
-      "when": 1731288423588,
-      "tag": "0000_cuddly_patriot",
+      "when": 1732400315508,
+      "tag": "0000_milky_hardball",
       "breakpoints": true
     },
     {
       "idx": 1,
       "version": "5",
-      "when": 1731290863632,
-      "tag": "0001_opposite_newton_destine",
-      "breakpoints": true
-    },
-    {
-      "idx": 2,
-      "version": "5",
-      "when": 1731296235880,
-      "tag": "0002_rainy_fantastic_four",
-      "breakpoints": true
-    },
-    {
-      "idx": 3,
-      "version": "5",
-      "when": 1731297339306,
-      "tag": "0003_lying_snowbird",
+      "when": 1732408530094,
+      "tag": "0001_freezing_supreme_intelligence",
       "breakpoints": true
     }
   ]