Migrate tooling to homelab; add OTel observability stack

- Remove GlitchTip, Umami, Fider, Gotify, Uptime Kuma, Dozzle, Watchtower
  from prod docker-compose (now run on homelab)
- Add dozzle-agent on prod (127.0.0.1:7007) for homelab Dozzle to connect to
- Remove corresponding subdomain blocks from Caddyfile (now routed via
  Cloudflare Tunnel from homelab)
- Add homelab/docker-compose.yml: unified homelab stack with all migrated
  tooling services plus full OTel stack (Tempo 2.6.1, Loki, Prometheus,
  OTel Collector, Grafana)
- Add homelab/otel/: Tempo, Loki, Prometheus, OTel Collector configs +
  Grafana provisioning (datasources + dashboards)
- Add homelab/dozzle/users.yml for Dozzle auth

Caddyfile

@@ -204,41 +204,11 @@
 }
 
 # ── Tooling subdomains ────────────────────────────────────────────────────────
-feedback.libnovel.cc {
-	import security_headers
-	reverse_proxy fider:3000
-}
-
-# ── GlitchTip: error tracking ─────────────────────────────────────────────────
-errors.libnovel.cc {
-	import security_headers
-	reverse_proxy glitchtip-web:8000
-}
-
-# ── Umami: page analytics ─────────────────────────────────────────────────────
-analytics.libnovel.cc {
-	import security_headers
-	reverse_proxy umami:3000
-}
-
-# ── Dozzle: Docker log viewer ─────────────────────────────────────────────────
-logs.libnovel.cc {
-	import security_headers
-	reverse_proxy dozzle:8080
-}
-
-# ── Uptime Kuma: uptime monitoring ────────────────────────────────────────────
-uptime.libnovel.cc {
-	import security_headers
-	reverse_proxy uptime-kuma:3001
-}
-
-# ── Gotify: push notifications ────────────────────────────────────────────────
-push.libnovel.cc {
-	import security_headers
-	reverse_proxy gotify:80
-}
-
+# feedback.libnovel.cc, errors.libnovel.cc, analytics.libnovel.cc,
+# logs.libnovel.cc, uptime.libnovel.cc, push.libnovel.cc, grafana.libnovel.cc
+# are now routed via Cloudflare Tunnel directly to the homelab (192.168.0.109).
+# No Caddy rules needed here — Cloudflare handles TLS termination and routing.
+
 # ── PocketBase: exposed for homelab runner task polling ───────────────────────
 # Allows the homelab runner to claim tasks and write results via the PB API.
 # Admin UI is also accessible here for convenience.