feat: require quests in Required; add deprioritize to quest-spawn

[kixelated]

Problem

A plain-text Required bullet is a condition outside the repository. The guide said to check periodically whether it had cleared, but nothing did. A blocked quest drops out of every quest ready listing, so these conditions get forgotten: moq-dev/moq's 2026-09-30 audit found two gates that had already cleared unnoticed (#4428, #4364).

This PR first added quest gates to list those bullets. It now takes the other approach: plain-text blockers are not allowed at all.

Change

• quest check rejects any Required entry that doesn't open with a link to a quest document. That includes plain text, issue or release URLs, and non-quest files. The error is requires X, which is not a quest document; make an outside condition its own quest.
• The guide says anything waiting on an outside party or a human action is its own quest. Its Goal names the condition and how to check or advance it, and the quest is deleted once the condition clears. Because it stays ready, it resurfaces at every /quest-spawn instead of stalling in the backlog.
• /quest-spawn checks whether an outside condition has cleared before making a recommendation. It also gains a deprioritize option (start, plan, skip, deprioritize, delete), which /quest-plan carries out.
• quest gates and its supporting refactor are removed, because a valid tree has no gates left to list.

Decisions

What does "deprioritize" do?

• Next milestone
• Bottom of its list
• ✅ Leave it vague: /quest-plan decides

How does spawn land it?

• One batched PR
• ✅ Via /quest-plan

Migration

Trees with plain-text Required bullets fail quest check after upgrading. moq-dev/moq has 14 of them, and each needs to become its own quest before moq bumps quest.

Validation

just check and just test pass (77 tests). The tests cover rejecting a plain-text condition, a wrapped bullet, and an external issue link. Fixtures that used plain-text bullets now link quests.

🤖 Generated with Claude Code

(written by Claude Opus 5.5)

[kixelated]

Merge summary

Changes: added quest gates [<path>] [--remote origin | --local]. It lists every plain-text Required bullet under the quest it blocks, in tree order, including gates on questline branches. ready and gates now share one tree-order walk. The guide and quest-audit point to the new command, and the README documents it.

Decisions:

• A new subcommand rather than a flag on ready.
• Grouped, indented output.
• Both the audit skill and the guide mention it. The CLI only prints the list; the agent decides whether a gate has cleared.

Review: reviewed by the maintainer. CI is green.

Follow-ups: none. moq picks this up on its next routine quest bump.

(written by Claude Opus 5.5)

[kixelated]

Repurposed. Plain-text Required bullets are now rejected, and every outside condition becomes its own quest, so quest gates is removed. The earlier merge summary no longer applies; the PR description is current. Migration note: moq-dev/moq's 14 gates must become quests before it bumps quest.

(written by Claude Opus 5.5)