docs: update ER diagram with all tables

docs/DATABASE.md

@@ -19,6 +19,10 @@ erDiagram
     users ||--o{ applications : "submits"
     users ||--o{ favorite_jobs : "saves"
     users ||--o{ notifications : "receives"
+    users ||--o{ tickets : "opens"
+    users ||--o{ ticket_messages : "sends"
+    users ||--o{ login_audits : "generates"
+    users ||--o{ activity_logs : "generates"
     
     companies ||--o{ user_companies : "has members"
     companies ||--o{ jobs : "posts"
@@ -31,6 +35,8 @@ erDiagram
     regions ||--o{ companies : "located in"
     regions ||--o{ jobs : "located in"
     
+    tickets ||--o{ ticket_messages : "contains"
+    
     %% Entities
     users {
         int id PK "SERIAL"
@@ -118,6 +124,45 @@ erDiagram
         varchar status
         varchar stripe_session_id
     }
+
+    tickets {
+        uuid id PK
+        int user_id FK
+        varchar subject
+        varchar status
+        varchar priority
+    }
+
+    ticket_messages {
+        uuid id PK
+        uuid ticket_id FK
+        int user_id FK
+        text message
+        boolean is_staff
+    }
+
+    job_posting_prices {
+        int id PK
+        varchar name
+        decimal price
+        int duration_days
+    }
+
+    login_audits {
+        int id PK
+        int user_id FK
+        varchar identifier
+        boolean success
+        varchar ip_address
+    }
+
+    activity_logs {
+        int id PK
+        int user_id FK
+        varchar entity_type
+        varchar action
+        jsonb details
+    }
 ```
 
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