fix: WireGuard routing, DNS, service access, and UI improvements

- Fix CoreDNS not loading .cell zones (wrong Corefile path, now uses -conf flag)
- Fix WireGuard server address conflict (172.20.0.1/16 overlapped with Docker
  network; changed to 10.0.0.1/24 to eliminate duplicate routes)
- Add SERVERMODE=true and sysctls to WireGuard docker-compose for server mode
- Fix DNS zone file parser to handle 4-field records (name IN type value)
- Add get_dns_records() to NetworkManager; mount data/dns into API container
- Fix peer config endpoint: look up IP/key from registry, use real endpoint
- Add bulk peer statuses endpoint keyed by public_key
- Normalize snake_case API fields to camelCase in WireGuard UI
- Add port check endpoint (checks via live handshake, not unreliable TCP probe)
- Add Caddy virtual hosts for ui/calendar/files/mail .cell domains (HTTP only)
- Fix cell config domain default from cell.local to cell
- Fix Routing Network Config tab (was calling hardcoded localhost:3000)
- Fix DNS records display (record.value not record.ip)
- Move service access guide to top of Dashboard with login hints
- Add /api/routing/setup endpoint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

config/dns/Corefile

@@ -1,42 +1,16 @@
-# Personal Internet Cell - CoreDNS Configuration
-# Handles .cell TLD resolution and peer discovery
-
-. {
-    # Forward all non-.cell domains to upstream DNS
-    forward . 8.8.8.8 1.1.1.1
-    
-    # Cache responses
-    cache
-    
-    # Log queries
-    log
-    
-    # Health check endpoint
-    health
-}
-
-# .cell TLD zone
-cell {
-    # File-based zone for static records
-    file /data/cell.zone
-    
-    # Dynamic peer records (will be managed by API)
-    reload
-    
-    # Allow zone transfers
-    transfer {
-        to *
-    }
-    
-    # Log queries
-    log
-}
-
-# Local network zone
-local.cell {
-    # File-based zone for local services
-    file /data/local.zone
-    
-    # Log queries
-    log
-} 
+. {
+    forward . 8.8.8.8 1.1.1.1
+    cache
+    log
+    health
+}
+
+cell {
+    file /data/cell.zone
+    log
+}
+
+local.cell {
+    file /data/local.zone
+    log
+}