platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/eventsbus/bus.go

@@ -0,0 +1,68 @@
+package eventsbus
+
+import (
+	"sync"
+	"time"
+)
+
+type Event struct {
+	ID   int64
+	Kind string
+	Ts   string
+	Data any
+}
+
+type Bus struct {
+	mu   sync.Mutex
+	cond *sync.Cond
+	buf  []Event
+	cap  int
+	next int64
+}
+
+func New(capacity int) *Bus {
+	if capacity < 16 {
+		capacity = 16
+	}
+	b := &Bus{
+		cap: capacity,
+		buf: make([]Event, 0, capacity),
+	}
+	b.cond = sync.NewCond(&b.mu)
+	return b
+}
+
+func (b *Bus) Push(kind string, data any) Event {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	b.next++
+	evt := Event{
+		ID:   b.next,
+		Kind: kind,
+		Ts:   time.Now().UTC().Format(time.RFC3339Nano),
+		Data: data,
+	}
+
+	if len(b.buf) >= b.cap {
+		b.buf = b.buf[1:]
+	}
+	b.buf = append(b.buf, evt)
+	b.cond.Broadcast()
+	return evt
+}
+
+func (b *Bus) Since(id int64) []Event {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if len(b.buf) == 0 {
+		return nil
+	}
+	out := make([]Event, 0, len(b.buf))
+	for _, ev := range b.buf {
+		if ev.ID > id {
+			out = append(out, ev)
+		}
+	}
+	return out
+}