Add GREMLINS.md documenting repo bots and agents (#4290)

Documents the automated agents operating on this repo. Starting with
Clawd (clockwork-labs-bot), the CI watchdog.

This is a living document — new bots/gremlins get documented here.

# API and ABI breaking changes
None — documentation only.

# Expected complexity level and risk
0 — documentation only.

# Testing
N/A — documentation only.

---------

Co-authored-by: clockwork-labs-bot <bot@clockworklabs.com>

.github/GREMLINS.md

@@ -0,0 +1,33 @@
+# GREMLINS.md — Who Lives in the Pipes
+
+This file documents the automated agents and bots that operate on this repository.
+
+## Clawd 🔧
+
+- **What:** Anti-entropy gremlin / CI watchdog
+- **GitHub account:** `clockwork-labs-bot`
+- **Discord channel:** #gremlins (CL - SpacetimeDB)
+- **Powered by:** [OpenClaw](https://github.com/openclaw/openclaw) + Claude
+
+### What Clawd does
+
+- **Monitors CI** — watches for failures, flaky tests, and regressions
+- **Reviews PRs** — comments on obvious bugs (never approves)
+- **Surfaces stale PRs** — finds approved PRs that just need a rebase
+- **Documents testing** — creates and maintains `DEVELOP.md` files explaining CI and test infrastructure
+- **Alerts the team** — posts findings in #gremlins, pings DevOps when something needs attention
+
+### What Clawd does NOT do
+
+- Approve or merge PRs
+- Take any destructive action (delete branches, close PRs, force push)
+- Modify production infrastructure
+
+### Contacting Clawd
+
+- Mention `@Openclaw` in #gremlins on Discord
+- Tag `@clockwork-labs-bot` on GitHub PRs/issues
+
+---
+
+*To add a new gremlin, document it here.*