0.7.1 [BREAKING CHANGE] Phase 4: Relocate quest roles under skill, add Codex orchestration (BETA)

What's Changed

• Add Codex thin wrapper integration by @KjellKod in #38
• Phase 4: Relocate quest roles under skill, add Codex orchestration (BETA) by @KjellKod in #39

Full Changelog: 0.6.1...0.7.1

What breaks:

The installer previously installed role files to .ai/roles/*_agent.md.

This branch moves them to .skills/quest/agents/*.md. The installer will:

1. Create the new files at .skills/quest/agents/*.md (good)
2. Leave the old .ai/roles/*_agent.md files in place (bad — stale references, potential
   confusion)

The installer has no concept of "delete files that were removed upstream." It only
creates and updates — it never removes.

After updating, manually remove the old role files that were relocated:

rm .ai/roles/arbiter_agent.md
rm .ai/roles/builder_agent.md
rm .ai/roles/code_review_agent.md
rm .ai/roles/fixer_agent.md
rm .ai/roles/plan_review_agent.md
rm .ai/roles/planner_agent.md

.ai/roles/quest_agent.md stays — it was not relocated.

You can verify with: bash scripts/validate-quest-config.sh