feat(idlewatcher): implement real-time SSE-based loading page with enhanced UX

This major overhaul of the idlewatcher system introduces a modern, real-time loading experience with Server-Sent Events (SSE) streaming and improved error handling.

- **Real-time Event Streaming**: New SSE endpoint (`/$godoxy/wake-events`) provides live updates during container wake process
- **Enhanced Loading Page**: Modern console-style interface with timestamped events and color-coded status messages
- **Improved Static Asset Management**: Dedicated paths for CSS, JS, and favicon to avoid conflicting with upstream assets
- **Event History Buffer**: Stores wake events for reconnecting clients and debugging

- Refactored HTTP request handling with cleaner static asset routing
- Added `WakeEvent` system with structured event types (starting, waking_dep, dep_ready, container_woke, waiting_ready, ready, error)
- Implemented thread-safe event broadcasting using xsync.Map for concurrent SSE connections
- Enhanced error handling with detailed logging and user-friendly error messages
- Simplified loading page template system with better asset path management
- Fixed race conditions in dependency waking and state management

- Removed `common.go` functions (canceled, waitStarted) - moved inline for better context
- Updated Waker interface to accept context parameter in Wake() method
- New static asset paths use `/$godoxy/` prefix to avoid conflicts

- Console-style output with Fira Code font for better readability
- Color-coded event types (yellow for starting, blue for dependencies, green for success, red for errors)
- Automatic page refresh when container becomes ready
- Improved visual design with better glassmorphism effects and responsive layout
- Real-time progress feedback during dependency wake and container startup

This change transforms the static loading page into a dynamic, informative experience that keeps users informed during the wake process while maintaining backward compatibility with existing routing behavior.

internal/idlewatcher/state.go

@@ -24,6 +24,8 @@ func (w *Watcher) setReady() {
 		status: idlewatcher.ContainerStatusRunning,
 		ready:  true,
 	})
+	// Send ready event via SSE
+	w.sendEvent(WakeEventReady, w.cfg.ContainerName()+" is ready!", nil)
 	// Notify waiting handlers that container is ready
 	select {
 	case w.readyNotifyCh <- struct{}{}:
@@ -42,6 +44,7 @@ func (w *Watcher) setStarting() {
 }
 
 func (w *Watcher) setNapping(status idlewatcher.ContainerStatus) {
+	w.clearEventHistory() // Clear events on stop/pause
 	w.state.Store(&containerState{
 		status:      status,
 		ready:       false,
@@ -51,6 +54,7 @@ func (w *Watcher) setNapping(status idlewatcher.ContainerStatus) {
 }
 
 func (w *Watcher) setError(err error) {
+	w.sendEvent(WakeEventError, "Container error", err)
 	w.state.Store(&containerState{
 		status:      idlewatcher.ContainerStatusError,
 		ready:       false,
@@ -76,3 +80,12 @@ func (w *Watcher) waitForReady(ctx context.Context) bool {
 		return false
 	}
 }
+
+func (w *Watcher) waitStarted(reqCtx context.Context) bool {
+	select {
+	case <-reqCtx.Done():
+		return false
+	case <-w.route.Started():
+		return true
+	}
+}