Write a SpacetimeDB backend module in C# that defines one table and seeds two rows.

TABLE
- Account (public)
  - Struct: Account
  - Fields:
    - Id: ulong (primary key, auto-increment)
    - Email: string (unique)
    - Name: string
  - Indexes:
    - by_name: btree(Name)

REDUCERS
- Seed: insert exactly these rows into Account (IDs are auto-assigned)
  - (Email="a@example.com", Name="Alice")
  - (Email="b@example.com", Name="Bob")
