Add navbar and home page with search functionality

- Create new home page (/) with overview stats, ASN lookup,
  AS name search, and IP address lookup with JSON display
- Add responsive navbar to all pages with app branding
- Navbar shows "routewatch by @sneak" with link to author
- Status page accessible via navbar link
- Remove redirect from / to /status, serve home page instead

internal/templates/templates.go

@@ -12,6 +12,9 @@ import (
 	"git.eeqj.de/sneak/routewatch/internal/version"
 )
 
+//go:embed index.html
+var indexHTML string
+
 //go:embed status.html
 var statusHTML string
 
@@ -26,6 +29,8 @@ var prefixLengthHTML string
 
 // Templates contains all parsed templates
 type Templates struct {
+	// Index is the template for the home page
+	Index *template.Template
 	// Status is the template for the main status page
 	Status *template.Template
 	// ASDetail is the template for displaying AS (Autonomous System) details
@@ -116,6 +121,12 @@ func initTemplates() {
 		"appGitCommitURL":  func() string { return version.CommitURL() },
 	}
 
+	// Parse index template
+	defaultTemplates.Index, err = template.New("index").Funcs(funcs).Parse(indexHTML)
+	if err != nil {
+		panic("failed to parse index template: " + err.Error())
+	}
+
 	// Parse status template
 	defaultTemplates.Status, err = template.New("status").Funcs(funcs).Parse(statusHTML)
 	if err != nil {
@@ -148,6 +159,11 @@ func Get() *Templates {
 	return defaultTemplates
 }
 
+// IndexTemplate returns the parsed index template
+func IndexTemplate() *template.Template {
+	return Get().Index
+}
+
 // StatusTemplate returns the parsed status template
 func StatusTemplate() *template.Template {
 	return Get().Status