Update an existing documentation file in .chalk/docs/.

Workflow

1. Find the doc — Search .chalk/docs/ for the file matching $ARGUMENTS. Match by filename, path, or content. If ambiguous, list candidates and ask the user to clarify.
2. Read current content — Load the file to understand what exists.
3. Apply changes — Update the content per the user's request. Preserve existing structure and sections where possible. Don't remove content unless explicitly asked.
4. Update the "Last updated" line — Set to today's date with a brief change note describing what changed.
5. Write the file — Save back to the same path.
6. Confirm — Tell the user what was changed and the file path.

Rules

• Preserve structure — Keep existing # and ## headings intact unless the user asks to reorganize.
• Update, don't rewrite — Modify the specific sections relevant to the change. Don't rewrite unrelated content.
• Last updated is required — Always update the date line. Format: Last updated: YYYY-MM-DD (<brief change note>).
• No frontmatter — Docs are plain markdown. Don't add YAML frontmatter.
• Respect the vertical's tone — Product docs are business-facing, AI docs are agent-facing reference-style, Engineering docs are technical and comprehensive.

Finding Docs

Search strategies in order of preference:

1. Exact path — If the user provides a path like "ai/0_AI_PROFILE.md", use it directly.
2. Filename match — Glob for **/[slug]*.md in .chalk/docs/.
3. Content search — Grep for keywords in .chalk/docs/**/*.md.
4. Vertical + topic — If the user says "the engineering architecture doc", search engineering/ for architecture-related filenames.