fix(staging): use HTTPS staging domains for all client URLs

- Updated all _CLIENT environment variables to use HTTPS staging domains
- Updated CORS_ORIGINS to allow HTTPS staging domains
- Added Caddyfile.staging to version control for documentation

Domain mappings:
- auth.staging.manacore.ai → mana-core-auth:3001
- chat.staging.manacore.ai → chat-web:3000
- chat-api.staging.manacore.ai → chat-backend:3002
- staging.manacore.ai → manacore-web:5173
- calendar.staging.manacore.ai → calendar-web:5186
- calendar-api.staging.manacore.ai → calendar-backend:3016
- clock.staging.manacore.ai → clock-web:5187
- clock-api.staging.manacore.ai → clock-backend:3017
- todo.staging.manacore.ai → todo-web:5188
- todo-api.staging.manacore.ai → todo-backend:3018

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

docker/caddy/Caddyfile.staging

@@ -0,0 +1,45 @@
+# ManaCore Staging Reverse Proxy
+# Deploy to: ~/Caddyfile on staging server (46.224.108.214)
+# Reload with: docker exec caddy caddy reload --config /etc/caddy/Caddyfile
+
+# Auth service
+auth.staging.manacore.ai {
+    reverse_proxy localhost:3001
+}
+
+# Chat
+chat.staging.manacore.ai {
+    reverse_proxy localhost:3000
+}
+chat-api.staging.manacore.ai {
+    reverse_proxy localhost:3002
+}
+
+# ManaCore main
+staging.manacore.ai {
+    reverse_proxy localhost:5173
+}
+
+# Calendar
+calendar.staging.manacore.ai {
+    reverse_proxy localhost:5186
+}
+calendar-api.staging.manacore.ai {
+    reverse_proxy localhost:3016
+}
+
+# Clock
+clock.staging.manacore.ai {
+    reverse_proxy localhost:5187
+}
+clock-api.staging.manacore.ai {
+    reverse_proxy localhost:3017
+}
+
+# Todo
+todo.staging.manacore.ai {
+    reverse_proxy localhost:5188
+}
+todo-api.staging.manacore.ai {
+    reverse_proxy localhost:3018
+}