Agent Pipeline for Codex v0.9.1

Summary

v0.9.1 syncs the release identity across the install/runtime/public docs surfaces and preserves the role-prompt patch from PR #7.

Added

• local-rehearsal.md Step 2.5 mandates regression-vs-baseline isolation on any verify-release.sh failure or hang.
• verifier.md cross-references Step 2.5 when verifier test runs diverge from implementation-report.md.
• Discussion seed post for the v0.9.1 baseline-isolation announcement.

Changed

• Plugin metadata, README, USER-MANUAL, landing page, bundled agent-pipeline reference docs, discussion seed docs, and script --version outputs now identify 0.9.1 consistently.

Verification

• python -m pytest -x: PASS, 104 passed, 1 warning.
• python scripts/verify_plugin_release.py --source-only: PASS.
• Browser QA for docs/index.html: desktop and mobile render current v0.9.1 release state; console clean.
• Main CI: PASS, run 26404647839.
• GitHub Pages deploy: PASS, run 26404646708.
• Local installed cache refreshed from corrected v0.9.1 tag; plugin install acceptance PASS.