docs: update STATUS.md with rate limiting incident response (#630)

- documented PR #629 rate limiting fix for moderation endpoint
- added tip to status-update command suggesting use after /deploy

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.5 <[e-mail]>

.claude/commands/status-update.md

···
 - deployment/infrastructure changes
 - incidents and their resolutions
 
+**tip**: after running `/deploy`, consider running `/status-update` to document what shipped.
+
 ## how to update
 
 1. add a new subsection under `## recent work` with today's date

STATUS.md

···
 
 ### December 2025
 
+#### rate limit moderation endpoint (PR #629, Dec 21)
+
+**incident response**: detected suspicious activity - 72 requests in 17 seconds from a single IP targeting `/moderation/sensitive-images`. investigation via Logfire showed:
+- single IP generating all traffic with no User-Agent header
+- requests spaced ~230ms apart (too consistent for human browsing)
+- no corresponding user activity (page loads, audio streams)
+
+**fix**: added `10/minute` rate limit to the endpoint using existing slowapi infrastructure. verified rate limiting works correctly post-deployment.
+
+---
+
 #### end-of-year sprint (Dec 20-31)
 
 **focus**: two foundational systems need solid experimental implementations by 2026.
···
 
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-this is a living document. last updated 2025-12-20.
+this is a living document. last updated 2025-12-21.