feat(server/m7-363): branding-aware index handler with html/template

web/embed.go

@@ -10,6 +10,8 @@ import (
 	"net/http"
 	"path"
 	"strings"
+
+	"git.fabledsword.com/bvandeusen/minstrel/internal/config"
 )
 
 //go:embed all:build
@@ -24,7 +26,10 @@ var buildFS embed.FS
 //
 // Callers are expected to register this as the router's NotFound/catch-all so
 // explicitly-routed paths (like /api/* and /rest/*) take precedence.
-func Handler() http.Handler {
+//
+// The branding parameter is applied to index.html once at construction via
+// html/template; all requests serve the resulting cached bytes.
+func Handler(branding config.BrandingConfig) http.Handler {
 	sub, err := fs.Sub(buildFS, "build")
 	if err != nil {
 		// fs.Sub on a valid embed path can only fail if the embed directive
@@ -32,11 +37,16 @@ func Handler() http.Handler {
 		panic("web: fs.Sub(build) failed: " + err.Error())
 	}
 
-	index, err := fs.ReadFile(sub, "index.html")
+	raw, err := fs.ReadFile(sub, "index.html")
 	if err != nil {
 		panic("web: embedded build/index.html missing: " + err.Error())
 	}
 
+	index, err := applyBrandingTemplate(string(raw), branding)
+	if err != nil {
+		panic("web: branding template failed: " + err.Error())
+	}
+
 	fileServer := http.FileServer(http.FS(sub))
 
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {