Remove BGP keepalive logging and add peer tracking

- Created bgp_peers table to track all BGP peers
- Added PeerHandler to update peer last seen times for all message types
- Removed verbose BGP keepalive debug logging
- BGP keepalive messages now silently update peer tracking

Refactor HTML templates to use go:embed

- Created internal/templates package with embedded templates
- Moved status.html from inline const to separate file
- Templates are parsed once on startup
- Server now uses parsed template instead of raw string

Optimize AS data embedding with gzip compression

- Changed asinfo package to embed gzipped data (2.4MB vs 12MB)
- Updated Makefile to gzip AS data during update
- Added decompression during initialization
- Raw JSON file excluded from git

internal/templates/templates.go

@@ -0,0 +1,48 @@
+// Package templates provides embedded HTML templates for the RouteWatch application
+package templates
+
+import (
+	_ "embed"
+	"html/template"
+	"sync"
+)
+
+//go:embed status.html
+var statusHTML string
+
+// Templates contains all parsed templates
+type Templates struct {
+	Status *template.Template
+}
+
+var (
+	//nolint:gochecknoglobals // Singleton pattern for templates
+	defaultTemplates *Templates
+	//nolint:gochecknoglobals // Singleton pattern for templates
+	once sync.Once
+)
+
+// initTemplates parses all embedded templates
+func initTemplates() {
+	var err error
+
+	defaultTemplates = &Templates{}
+
+	// Parse status template
+	defaultTemplates.Status, err = template.New("status").Parse(statusHTML)
+	if err != nil {
+		panic("failed to parse status template: " + err.Error())
+	}
+}
+
+// Get returns the singleton Templates instance
+func Get() *Templates {
+	once.Do(initTemplates)
+
+	return defaultTemplates
+}
+
+// StatusTemplate returns the parsed status template
+func StatusTemplate() *template.Template {
+	return Get().Status
+}