[FEATURE] Task queue for queuing multiple prompts/tasks

Problem

There's no way to queue up multiple tasks and have them execute sequentially or in parallel. When working on a complex project, I often know the next 3-5 things Claude needs to do, but I have to wait for each one to finish before giving the next instruction.

OpenAI Codex CLI already ships this as a core feature — users can queue tasks and they run in sandboxed environments.

Proposed Solution

• Allow users to queue multiple prompts/tasks
• Execute them sequentially (or optionally in parallel with worktree isolation)
• Show queue status and results when done
• Persist queue across rate limit resets

Prior Issues (all auto-closed by stale bot, not by team decision)

• #535 — "The ability to queue up messages" (27+ upvotes, auto-closed)
• #15854 — "Programmatic access to message queue" (auto-closed)
• #1314 — "Queue for when Max limit refreshes" (auto-closed)
• #7244 — "/wait command for scheduled execution" (auto-closed)

These were all closed by GitHub Actions bot due to inactivity, not because the feature was reviewed and rejected. The demand is clearly there.