Co-Authored-By: Virgil <virgil@lethean.io>
Add Issue, Sprint, IssueComment models with workspace scoping, soft deletes, activity logging, and MCP context support. Migration creates issues, sprints, and issue_comments tables. API routes registered with read/write permission scopes. Controller stubs for IssueController and SprintController. Co-Authored-By: Virgil <virgil@lethean.io>