fix: correct stats/visualize API URL construction for frontend

Frontend uses `new URL(path, host)` — when path starts with `/`, JS URL
constructor ignores any path in the host. So putting `/stats-api` in
STATS_API_HOST was silently broken (browser hit wrong endpoint → N/A).

- Mainnet: use subdomain (stats.doscan.io, viz.doscan.io)
- Testnet/Beta: split HOST and BASE_PATH correctly

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

Author: JOY

docker-compose/envs/common-frontend-beta.env

@@ -197,12 +197,14 @@ NEXT_PUBLIC_HAS_USER_OPS=true
 # =============================================================================
 # FEATURE: STATS SERVICE
 # =============================================================================
-NEXT_PUBLIC_STATS_API_HOST=https://beta-stats.doscan.io
+NEXT_PUBLIC_STATS_API_HOST=https://beta.doscan.io
+NEXT_PUBLIC_STATS_API_BASE_PATH=/stats-api
 
 # =============================================================================
 # FEATURE: VISUALIZE API
 # =============================================================================
-NEXT_PUBLIC_VISUALIZE_API_HOST=https://beta-viz.doscan.io
+NEXT_PUBLIC_VISUALIZE_API_HOST=https://beta.doscan.io
+NEXT_PUBLIC_VISUALIZE_API_BASE_PATH=/visualize
 
 # =============================================================================
 # FEATURE: METADATA SERVICE

docker-compose/envs/common-frontend-testnet.env

@@ -258,14 +258,14 @@ NEXT_PUBLIC_MARKETPLACE_CATEGORIES_URL=https://raw.githubusercontent.com/DOSLabs
 # =============================================================================
 # FEATURE: SOLIDITY TO UML
 # =============================================================================
-NEXT_PUBLIC_VISUALIZE_API_HOST=https://test.doscan.io/visualize
-# NEXT_PUBLIC_VISUALIZE_API_BASE_PATH=
+NEXT_PUBLIC_VISUALIZE_API_HOST=https://test.doscan.io
+NEXT_PUBLIC_VISUALIZE_API_BASE_PATH=/visualize
 
 # =============================================================================
 # FEATURE: BLOCKCHAIN STATISTICS
 # =============================================================================
-NEXT_PUBLIC_STATS_API_HOST=https://test.doscan.io/stats-api
-# NEXT_PUBLIC_STATS_API_BASE_PATH=
+NEXT_PUBLIC_STATS_API_HOST=https://test.doscan.io
+NEXT_PUBLIC_STATS_API_BASE_PATH=/stats-api
 
 # =============================================================================
 # FEATURE: WEB3 WALLET INTEGRATION

docker-compose/envs/common-frontend.env

@@ -197,12 +197,12 @@ NEXT_PUBLIC_HAS_USER_OPS=true
 # =============================================================================
 # FEATURE: STATS SERVICE
 # =============================================================================
-NEXT_PUBLIC_STATS_API_HOST=https://doscan.io/stats-api
+NEXT_PUBLIC_STATS_API_HOST=https://stats.doscan.io
 
 # =============================================================================
 # FEATURE: VISUALIZE API
 # =============================================================================
-NEXT_PUBLIC_VISUALIZE_API_HOST=https://doscan.io/visualize
+NEXT_PUBLIC_VISUALIZE_API_HOST=https://viz.doscan.io
 
 # =============================================================================
 # FEATURE: METADATA SERVICE