Update all web links to use petz.rdx4.com domain

🌐 Updated URLs:
- \!help command now points to http://petz.rdx4.com/help
- \!pets command now points to http://petz.rdx4.com/player/{nickname}
- README.md updated to reference petz.rdx4.com
- Web server startup messages show both local and public URLs

🔧 Changes:
- modules/core_commands.py: Updated help URL
- modules/pet_management.py: Updated player profile URL
- webserver.py: Added public URL display in startup messages
- README.md: Updated web interface section

Users will now receive public URLs that work externally instead of localhost URLs.

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

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

webserver.py

@@ -1453,6 +1453,7 @@ class PetBotWebServer:
         thread = Thread(target=self.run, daemon=True)
         thread.start()
         print(f"✅ Web server started at http://localhost:{self.port}")
+        print(f"🌐 Public access at: http://petz.rdx4.com/")
         return thread
 
 def run_standalone():
@@ -1469,11 +1470,18 @@ def run_standalone():
     server = PetBotWebServer(database)
     print("🚀 Starting web server...")
     print("📝 Available routes:")
-    print("   http://localhost:8080/        - Game Hub")
-    print("   http://localhost:8080/help    - Command Help") 
-    print("   http://localhost:8080/players - Player List")
-    print("   http://localhost:8080/leaderboard - Leaderboard")
-    print("   http://localhost:8080/locations - Locations")
+    print("   http://localhost:8080/        - Game Hub (local)")
+    print("   http://localhost:8080/help    - Command Help (local)") 
+    print("   http://localhost:8080/players - Player List (local)")
+    print("   http://localhost:8080/leaderboard - Leaderboard (local)")
+    print("   http://localhost:8080/locations - Locations (local)")
+    print("")
+    print("🌐 Public URLs:")
+    print("   http://petz.rdx4.com/         - Game Hub")
+    print("   http://petz.rdx4.com/help     - Command Help") 
+    print("   http://petz.rdx4.com/players  - Player List")
+    print("   http://petz.rdx4.com/leaderboard - Leaderboard")
+    print("   http://petz.rdx4.com/locations - Locations")
     print("")
     print("Press Ctrl+C to stop")