Drop HOST_PORT env override, hardcode 8080

Unnecessary flexibility — port doesn't need to be configurable.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.env.example

@@ -11,6 +11,3 @@ SECRET_KEY=change-me-to-a-long-random-string
 # Keep "true" in production (TLS terminated by a reverse proxy in front, e.g. Pangolin).
 # Only set to "false" for local testing without any TLS in front.
 COOKIE_SECURE=true
-
-# Local port the site is reachable on (http://localhost:<HOST_PORT>).
-HOST_PORT=8080

docker-compose.yml

@@ -7,7 +7,7 @@ services:
     image: gitea.honeyy.duckdns.org/website/honey-links:latest
     build: .
     ports:
-      - "${HOST_PORT:-8080}:80"
+      - "8080:80"
     environment:
       - ADMIN_PASSWORD=${ADMIN_PASSWORD}
       - SECRET_KEY=${SECRET_KEY}