feat(gemini): add deep-research workflow and docs export result

[backtomyfuture]

Summary

• add gemini deep-research command to start Gemini Deep Research from a prompt and return the started conversation URL
• add gemini deep-research-result command to export Deep Research output via Share & Export -> Export to Docs and return the Google Docs URL
• extend Gemini utility helpers with robust conversation selection, tool selection, confirm-button polling, and Docs URL extraction (including Drive upload response id fallback)
• improve deep-research submission reliability by verifying prompt submission after send, retrying once when submission is not detected, and returning submit-not-found when both attempts fail
• support newer Deep Research confirm labels in Gemini UI (including phrases like Generate research plan / 生成研究计划)
• improve deep-research-result behavior for in-progress sessions: when export URL is not yet available and research is still running, return a waiting message instead of a misleading no-docs error
• add/expand adapter tests for new commands, submit retry/failure paths, confirm label compatibility, export URL picking behavior, and in-progress result handling

Behavior Changes

• opencli gemini deep-research "<prompt>" -f json
  • now validates that submission actually happened
  • retries once automatically if submit did not stick
  • may return:
    • started
    • tool-not-found
    • submit-not-found
    • confirm-not-found
• opencli gemini deep-research-result "<conversation-url>" -f json
  • returns Docs URL when export succeeds
  • returns Deep Research is still running. Please wait and retry later. when the research job is still in progress
  • returns no-docs guidance only when not in running state and no export URL is found

Verification

• npx tsc --noEmit
• npx vitest run --project adapter src/clis/gemini
• npm run build
• node dist/main.js gemini deep-research "今日10条AI相关新闻" -f json
• node dist/main.js gemini deep-research-result "https://gemini.google.com/app/<conversation-id>" -f json