fix(healthcheck): sweep localhost -> 127.0.0.1 across all 48 templates

BusyBox wget (+ node/python/curl one-shots, incl mealie's socket tuple) resolve
localhost -> IPv6 ::1 with no cross-family fallback; an IPv4-only-binding app
reads docker-unhealthy while serving (vaultwarden, re-run 2026-07-06). Escalates
that instance to the class. Scoped strictly to healthcheck test: lines
(diff-reviewed: no env/config/label changed; .felhom.yml already clean). New
REUSE.md convention row.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6

templates/calcom/docker-compose.yml

@@ -42,7 +42,7 @@ services:
           memory: 768M
     healthcheck:
       # GET (-O /dev/null), not --spider (HEAD): the Next.js API route rejects HEAD, so --spider flaps unhealthy.
-      test: ["CMD", "wget", "-q", "-O", "/dev/null", "http://localhost:3000/api/auth/providers"]
+      test: ["CMD", "wget", "-q", "-O", "/dev/null", "http://127.0.0.1:3000/api/auth/providers"]
       interval: 30s
       timeout: 5s
       retries: 3