refactor: streamline routes to RESTful naming conventions

Remove /api/ prefix and consolidate route groups:
- /api/lobby/* -> /games, /snake, /logout (top-level)
- /game/{game_id} + /api/game/{game_id}/* -> /games/{id}/*
- /snake/{game_id} + /api/snake/{game_id}/* -> /snake/{id}/*
- /api/auth/* -> /auth/*
- Standardize snake join page to use return_url= (was return=)

features/snakegame/pages/game_templ.go

@@ -27,10 +27,10 @@ func keydownScript(gameID string) string {
 			"else if(k==='s'||k==='ArrowDown'){evt.preventDefault();%s}"+
 			"else if(k==='a'||k==='ArrowLeft'){evt.preventDefault();%s}"+
 			"else if(k==='d'||k==='ArrowRight'){evt.preventDefault();%s}",
-		datastar.PostSSE("/api/snake/%s/dir?d=0", gameID),
-		datastar.PostSSE("/api/snake/%s/dir?d=1", gameID),
-		datastar.PostSSE("/api/snake/%s/dir?d=2", gameID),
-		datastar.PostSSE("/api/snake/%s/dir?d=3", gameID),
+		datastar.PostSSE("/snake/%s/dir?d=0", gameID),
+		datastar.PostSSE("/snake/%s/dir?d=1", gameID),
+		datastar.PostSSE("/snake/%s/dir?d=2", gameID),
+		datastar.PostSSE("/snake/%s/dir?d=3", gameID),
 	)
 }
 
@@ -210,8 +210,8 @@ func JoinPage(gameID string) templ.Component {
 			}
 			ctx = templ.InitializeContext(ctx)
 			templ_7745c5c3_Err = components.GameJoinPrompt(
-				fmt.Sprintf("/login?return=/snake/%s", gameID),
-				fmt.Sprintf("/register?return=/snake/%s", gameID),
+				fmt.Sprintf("/login?return_url=/snake/%s", gameID),
+				fmt.Sprintf("/register?return_url=/snake/%s", gameID),
 				fmt.Sprintf("/snake/%s", gameID),
 			).Render(ctx, templ_7745c5c3_Buffer)
 			if templ_7745c5c3_Err != nil {
@@ -260,7 +260,7 @@ func NicknamePage(gameID string) templ.Component {
 				}()
 			}
 			ctx = templ.InitializeContext(ctx)
-			templ_7745c5c3_Err = components.NicknamePrompt(fmt.Sprintf("/api/snake/%s/join", gameID)).Render(ctx, templ_7745c5c3_Buffer)
+			templ_7745c5c3_Err = components.NicknamePrompt(fmt.Sprintf("/snake/%s/join", gameID)).Render(ctx, templ_7745c5c3_Buffer)
 			if templ_7745c5c3_Err != nil {
 				return templ_7745c5c3_Err
 			}