chore: run go fix for Go 1.26 modernization

106 files: interface{}→any, strings.Split→SplitSeq, CutPrefix/Cut, strings.Builder, slices.Contains, remove redundant // +build directives, gofmt import ordering and indentation.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/mw/auth.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"log"
 	"net/http"
+	"slices"
 	"strings"
 
 	"crussell/auth"
@@ -77,13 +78,7 @@ func RequireRole(allowedRoles ...string) func(http.Handler) http.Handler {
 			}
 
 			// Check if user has one of the allowed roles
-			hasRole := false
-			for _, allowedRole := range allowedRoles {
-				if role == allowedRole {
-					hasRole = true
-					break
-				}
-			}
+			hasRole := slices.Contains(allowedRoles, role)
 
 			if !hasRole {
 				http.Error(w, "forbidden", http.StatusForbidden)

backend/mw/auth_test.go

@@ -1,5 +1,4 @@
 //go:build test
-// +build test
 
 package mw
 

backend/mw/contenttype_test.go

@@ -1,5 +1,4 @@
 //go:build test
-// +build test
 
 package mw
 

backend/mw/ratelimit.go

@@ -1,5 +1,4 @@
 //go:build !dev
-// +build !dev
 
 package mw
 

backend/mw/ratelimit_dev.go

@@ -1,5 +1,4 @@
 //go:build dev
-// +build dev
 
 package mw
 

backend/mw/ratelimit_dev_test.go

@@ -1,5 +1,4 @@
 //go:build test && dev
-// +build test,dev
 
 package mw
 

backend/mw/ratelimit_prod_test.go

@@ -1,5 +1,4 @@
 //go:build test && !dev
-// +build test,!dev
 
 package mw
 

backend/mw/ratelimit_test.go

@@ -1,5 +1,4 @@
 //go:build test && !dev
-// +build test,!dev
 
 package mw