docs: add UI patrol schedule readiness evidence

[wlsdks]

Summary

• Add docs/UI_PATROL_SCHEDULE_READINESS_2026-07-06.md as a separate scheduled UI patrol readiness ledger.
• Expose scheduled_ui_patrol_preflight in quality-evidence for the web operations axis.
• Keep scheduled_ui_patrol pending until a real GitHub Actions schedule event uploads a 9-png ui-patrol-screenshots artifact.
• Package and guard the readiness ledger so installed users and future agents see the same evidence boundary.

Effect Check

• web_ui_and_operational_evidence now shows scheduled_ui_patrol_preflight as satisfied evidence.
• promptlane_95_quality remains pending with the same four blockers.
• This improves operational clarity without pretending workflow_dispatch evidence completes cron evidence.

Verification

• RED: focused quality/plugin tests failed before implementation because the readiness ledger and scheduled_ui_patrol_preflight were missing.
• GREEN: corepack pnpm vitest run src/cli/commands/quality-evidence.test.ts src/packaging/quality-evidence-script.test.ts src/packaging/plugin-files.test.ts --testNamePattern "quality|preflight|scheduled ui-patrol"
• corepack pnpm --silent evidence:quality | node -e '...'
• node dist/cli/index.js quality-evidence | sed -n '1,45p'
• corepack pnpm test
• corepack pnpm lint
• corepack pnpm build
• corepack pnpm pack:dry-run
• git diff --check