fix: task.next events not firing on project dependency completion

[danielkov]

Summary

• The trg_task_next_on_project_dep_completed trigger checked for project status 'done' but auto-complete sets projects to 'completed' — a status the trigger didn't recognize
• Workers subscribing to task.next events were never notified when project dependencies were satisfied through auto-completion, causing tasks to sit idle despite being actionable via granary next --all
• Add 'completed' to the trigger's WHEN clause and all related project dependency status checks

Root cause

The auto-complete trigger (trg_project_auto_complete) sets projects to status 'completed', but the cascade trigger (trg_task_next_on_project_dep_completed) only fires when NEW.status IN ('done', 'archived'). Since no code path ever sets a project to 'done', this cascade trigger has never fired — meaning task.next events were never emitted when project dependencies were satisfied via task completion.

What changed

• Migration: Recreates trg_task_next_on_project_dep_completed with 'completed' in its WHEN clause, and all 6 task.next triggers with 'completed' in their project dependency status checks
• Rust queries: get_next, get_all_next, and initiative get_next updated to include 'completed' in NOT IN clauses (defensive)
• Tests: Two new trigger tests verifying task.next is emitted when project deps are satisfied via auto-complete, and not emitted when only partial deps are satisfied

✻ Clauded...