docs: public-readiness — vibe-coded disclosure + genericize internal hosts

- README + CLAUDE.md: upfront "this is a vibe-coded project" disclosure for
  going public.
- Replace internal LAN hostnames (*.orgrimmar.dudenhoeffer.casa) with
  example.com across README, ADR-0004, the envproviders example, and env_test.go
  (assertions updated together; suite still green). Token was already a
  "change-me" placeholder, not a real secret.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/adr/0004-env-dsn-providers.md

@@ -8,8 +8,8 @@ Steve's deployments define providers via env vars that must keep working
 unchanged:
 
 ```
-LLM_M1=foreman://token@foreman-m1.orgrimmar.dudenhoeffer.casa
-LLM_M5=foreman://token@foreman-m5.orgrimmar.dudenhoeffer.casa
+LLM_M1=foreman://token@foreman-m1.example.com
+LLM_M5=foreman://token@foreman-m5.example.com
 ```
 
 go-llm (v2/parse.go) implements this **lazily only**: `Parse("m5/x")` misses