Add Caddy reverse proxy configuration for Matrix (#183)

infra/matrix/caddy/Caddyfile

@@ -0,0 +1,58 @@
+# Caddyfile — Reverse proxy for Conduit Matrix homeserver
+# Issue: #166 / #183
+#
+# Place in /etc/caddy/Caddyfile or use with `caddy run --config Caddyfile`
+
+# Matrix client and federation on same domain
+matrix.timmy.foundation {
+    # Client API (.well-known, /_matrix/client)
+    handle /.well-known/matrix/* {
+        header Content-Type application/json
+        respond `{"
+            "m.homeserver": {"base_url": "https://matrix.timmy.foundation"},
+            "m.identity_server": {"base_url": "https://vector.im"}
+        }` 200
+    }
+
+    # Handle federation (server-to-server) on standard path
+    handle /_matrix/server/* {
+        reverse_proxy localhost:6167
+    }
+
+    # Handle client API
+    handle /_matrix/client/* {
+        reverse_proxy localhost:6167
+    }
+
+    # Handle media repository
+    handle /_matrix/media/* {
+        reverse_proxy localhost:6167
+    }
+
+    # Handle federation checks
+    handle /_matrix/federation/* {
+        reverse_proxy localhost:6167
+    }
+
+    # Handle static content (if serving Element web from same domain)
+    handle_path /element/* {
+        reverse_proxy localhost:8080
+    }
+
+    # Health check / status
+    respond /health "OK" 200
+    
+    # Default — you may want to serve Element web or redirect
+    respond "Matrix Homeserver" 200
+}
+
+# Optional: Serve Element Web on separate subdomain
+# element.timmy.foundation {
+#     reverse_proxy localhost:8080
+# }
+
+# Federation port (8448) — server-to-server communication
+# This allows other Matrix servers to find and connect to yours
+matrix.timmy.foundation:8448 {
+    reverse_proxy localhost:6167
+}