[r/boards] initialize primary structs

[salmad3]

Context:

Threads and posts are core components of r/boards. Defining these structs establishes a consistent model for content management and supports features such as thread creation, post handling, and moderation. These structs should integrate with the Permissions interface to enable role-based actions.

Acceptance Criteria:

• Defines the Thread struct with attributes for board reference, creator, title, timestamp, post references, and lock status.

  Example

  type Thread struct {
      ID        int64
      BoardID   int64
      Creator   Address
      Title     string
      Timestamp time.Time
      Posts     []int64
      IsLocked  bool
  }

• Define the Post struct with attributes for thread reference, author, content, timestamp, and moderation flags.

  Example

  type Post struct {
      ID        int64
      ThreadID  int64
      Author    Address
      Content   string
      Timestamp time.Time
      Flags     []Flag
  }

• Implements basic methods for managing threads and posts, ensuring that:

  • Threads act as containers for posts.
  • The Post struct references the Thread it belongs to.
  • The Thread struct can maintain a list of post IDs or references.

• Implements a LockThread() method to mark a thread as locked to prevent new posts from being added.

• Ensures integration with Permissions for locking threads, so only users with the right roles can perform this action.

• Ensures that the structs are placed within the r/boards realm or an appropriate package (TBD).

• Integrates permission checks for creating and managing threads and posts using WithPermission().