[AZ-189] [AZ-190] [AZ-191] [AZ-192] [AZ-193] [AZ-194] [AZ-195] Add e2e blackbox test suite

Made-with: Cursor

_docs/02_document/modules/common_database_azaion_db.md

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+# Module: Azaion.Common.Database.AzaionDb
+
+## Purpose
+linq2db `DataConnection` subclass representing the application's database context.
+
+## Public Interface
+
+| Member | Type | Description |
+|--------|------|-------------|
+| Constructor | `AzaionDb(DataOptions dataOptions)` | Initializes connection with pre-configured options |
+| `Users` | `ITable<User>` | Typed table accessor for the `users` table |
+
+## Internal Logic
+Delegates all connection management to the base `DataConnection` class. `Users` property calls `this.GetTable<User>()`.
+
+## Dependencies
+- `User` entity
+- linq2db (`LinqToDB.Data.DataConnection`, `LinqToDB.ITable<T>`)
+
+## Consumers
+- `DbFactory` — creates `AzaionDb` instances inside `Run`/`RunAdmin` methods
+
+## Data Models
+Provides access to the `users` table.
+
+## Configuration
+Receives `DataOptions` (containing connection string + mapping schema) from `DbFactory`.
+
+## External Integrations
+PostgreSQL database via Npgsql.
+
+## Security
+None at this level; connection string security is handled by `DbFactory`.
+
+## Tests
+Indirectly used by `UserServiceTest`.