feat(virtualcam): add Google OAuth, enable Shkeeper payments, update Caddy rules

- Update virtualcam website and API to latest repository revisions.
- Add Google OAuth client ID and secrets decryption for Google auth.
- Enable Shkeeper BTC/USD payment processing (`BYPASS_PAYMENTS=false`) and add service dependencies.
- Update Caddy `admin_gate` IP access rules and remove redundant `admin_gate` import from app proxy.
- Configure weekly automatic Nix garbage collection (`--delete-older-than 14d`) and nix store optimization.

servers/hetzner/modules/services/caddy.nix

@@ -24,7 +24,7 @@ in {
     # Global Caddyfile snippets (shared across all virtual hosts).
     extraConfig = ''
       (admin_gate) {
-        @notvpn not remote_ip 10.8.0.0/24
+        @notvpn not remote_ip 127.0.0.1 ::1 10.8.0.0/24 fd10:8::/64 49.13.92.205 2a01:4f8:c014:2585::1
         respond @notvpn "Forbidden" 403
       }
       # Restrict access to the server itself (loopback + public IPs) or the
@@ -245,7 +245,6 @@ in {
           import security_headers
           import csp
           ${antiScrape}
-          import admin_gate
           reverse_proxy 127.0.0.1:5000
           encode zstd gzip
         '';