Refactor SkillBridge hot spot modules

[heznpc]

Summary

• Split content UI surface cleanup and chat message DOM helpers into focused modules
• Refactor GT queue, translator verify handling, and page-bridge translate/verify dispatch into smaller helpers
• Move the E2E Puter stream stub into its own helper file

Validation

• npm run lint
• npm run typecheck
• npm run format:check
• npm run build:bundle && npm run build:firefox
• CI validation scripts: validate translations, glossary, i18n, locale contamination, dict coverage, shared constants, dict freshness, plugin check, selector health
• npx jest --passWithNoTests --runInBand
• docs generation stale check
• npm run test:e2e (full 5-batch rerun passed)

Notes

• One idb-cache E2E run hit a timing failure once; the spec passed alone, batch 3 rerun, and the final full E2E rerun.