docs: add an agent install prompt to the readme quick start

[LivXue]

Summary

Both READMEs now open Quick Start with a short subsection for readers who would rather have their own agent install Raven. It holds one prompt to paste into any agent that can read a web page and run shell commands. The prompt sends the agent to the quick start page on the documentation site and asks it to install Raven, or to update it when it is already installed. The page covers both paths since its Update Raven section landed in #711, so this route adds no install steps to the README that could drift from the page.

The prompt sits in a fenced text block, which GitHub renders with a copy button, so one click copies the whole prompt. It stays on a single line so that pasting it cannot send half a prompt in an agent whose input submits on a newline. The Chinese README points at the Chinese page, as its documentation link already does.

Known gap, left to the page: an install that an agent runs by following the page ends on the WebUI in the foreground and does not return until it is stopped. The page's Update Raven section says a re-run of the installer finishes that way; the Install Raven section does not say the first install does the same, and neither names RAVEN_NO_LAUNCH=1, the setting that makes the installer return. That belongs to a separate docs-site change.

Type

• Fix
• Feature
• Docs
• CI / tooling
• Refactor
• Other

Verification

Every command ran against this branch's tree, with the project venv's Python.

• python -m pytest tests/test_cli_onboard_commands.py::test_readme_quickstart_matches_the_installer -q -o addopts="" -> 1 passed. This is the test that reads the Quick Start section of both READMEs.

• python scripts/check_commit_messages.py origin/main..HEAD -> exit 0.

• commitlint --from origin/main --to HEAD --config commitlint.config.cjs -> found 0 problems, 0 warnings.

• python scripts/check_large_files.py origin/main...HEAD and python scripts/check_source_language.py origin/main...HEAD -> exit 0 each.

• pre-commit run --from-ref origin/main --to-ref HEAD -> trailing whitespace, end of files, large files, merge conflicts and private key passed; every other hook had no files to check.

• Copy button, checked in headless Chromium at 1440x900 on this branch's blob view of both READMEs: the block carries GitHub's clipboard-copy button, the button shows on hover, and one click puts exactly the committed prompt on the clipboard (129 characters in README.md, 91 in README.zh-CN.md, no newline). The clipboard held a different string before the click, so a click that copied nothing would have failed.

• Both pages the prompts name return 200 and carry the Update Raven section: https://evermind-ai.github.io/Raven/quick-start/ and https://evermind-ai.github.io/Raven/zh/quick-start/

• The #-quick-start and #-install anchors are unchanged; the new heading adds #-install-with-your-agent.

• Relevant tests pass locally

• Relevant lint / type checks pass locally

• User-facing docs or screenshots are updated when needed

Risk

User-visible change: one new subsection at the top of Quick Start in both READMEs; nothing else in either file moves. The prompt asks an agent to read the project's documentation page and run the installer that page names, which is the same trust the README's own curl ... | bash line already asks of a reader. No existing anchor or link changes. Rollback is reverting this commit.

• Security impact considered
• Backward compatibility considered
• Rollback path is clear for risky changes

Related Issues

N/A

[gloryfromca]

No blockers; this can merge as far as I am concerned.

I reviewed the complete diff and surrounding README quick-start content, checked the linked English and Chinese documentation sources and their published routes, and examined the relevant README history. Both links return HTTP 200, and both pages document fresh installation and updating, so the new prompts accurately describe their targets. The English and Chinese additions remain aligned and comply with the repository's Markdown language exemption.

Checks passed:

• git diff --check github/main...HEAD
• uv run python scripts/check_source_language.py 'github/main...HEAD'
• uv run python scripts/check_large_files.py 'github/main...HEAD'

No tests were weakened or changed. This documentation-only change does not touch runtime callers, behavior, compatibility surfaces, or architecture boundaries.