Phase 2 backend: LiveKit voice integration

Backend:
- internal/voice/client.go: LiveKit token generation, room management, participant listing
- internal/voice/handlers.go: POST /voice/token, GET /voice/rooms/{roomID}/participants
- internal/gateway/events.go: added VOICE_JOIN, VOICE_LEAVE, VOICE_MUTE, VOICE_DEAFEN events
- cmd/server/main.go: wired voice client and routes under /api/v1/voice
- Docker: livekit.yaml config verified

Frontend deps:
- Added livekit-client and @livekit/components-react packages

internal/voice/handlers.go

@@ -0,0 +1,129 @@
+package voice
+
+import (
+	"database/sql"
+	"encoding/json"
+	"net/http"
+
+	"git.dustin.coffee/hobokenchicken/dumpsterChat/internal/gateway"
+	"git.dustin.coffee/hobokenchicken/dumpsterChat/internal/middleware"
+	"github.com/go-chi/chi/v5"
+	"github.com/livekit/protocol/livekit"
+)
+
+type Handler struct {
+	db     *sql.DB
+	client *Client
+	hub    *gateway.Hub
+}
+
+func NewHandler(db *sql.DB, client *Client, hub *gateway.Hub) *Handler {
+	return &Handler{
+		db:     db,
+		client: client,
+		hub:    hub,
+	}
+}
+
+func (h *Handler) RegisterRoutes(r chi.Router) {
+	r.Post("/token", h.GetToken)
+	r.Get("/rooms/{roomID}/participants", h.GetParticipants)
+}
+
+type tokenRequest struct {
+	RoomName string `json:"room_name"`
+}
+
+type tokenResponse struct {
+	Token      string `json:"token"`
+	LiveKitURL string `json:"livekit_url"`
+}
+
+func (h *Handler) GetToken(w http.ResponseWriter, r *http.Request) {
+	userID, ok := middleware.UserIDFromContext(r.Context())
+	if !ok {
+		http.Error(w, `{"error":"unauthorized"}`, http.StatusUnauthorized)
+		return
+	}
+
+	var req tokenRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, `{"error":"invalid request"}`, http.StatusBadRequest)
+		return
+	}
+
+	if req.RoomName == "" {
+		http.Error(w, `{"error":"missing room_name"}`, http.StatusBadRequest)
+		return
+	}
+
+	// Get username for the identity
+	var username string
+	err := h.db.QueryRowContext(r.Context(), `SELECT username FROM users WHERE id = $1`, userID).Scan(&username)
+	if err != nil {
+		http.Error(w, `{"error":"user not found"}`, http.StatusNotFound)
+		return
+	}
+
+	// Create room if it doesn't exist
+	_, err = h.client.CreateRoom(req.RoomName)
+	if err != nil {
+		// Room might already exist, that's fine
+	}
+
+	token, err := h.client.GenerateToken(req.RoomName, userID, username)
+	if err != nil {
+		http.Error(w, `{"error":"token generation failed"}`, http.StatusInternalServerError)
+		return
+	}
+
+	// Broadcast voice join event
+	h.hub.BroadcastEvent(gateway.Event{
+		Type: "VOICE_JOIN",
+		Data: map[string]interface{}{
+			"room_name": req.RoomName,
+			"user_id":   userID,
+			"username":  username,
+		},
+	})
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(tokenResponse{
+		Token:      token,
+		LiveKitURL: h.client.url,
+	})
+}
+
+func (h *Handler) GetParticipants(w http.ResponseWriter, r *http.Request) {
+	roomID := chi.URLParam(r, "roomID")
+	if roomID == "" {
+		http.Error(w, `{"error":"missing room ID"}`, http.StatusBadRequest)
+		return
+	}
+
+	participants, err := h.client.ListParticipants(roomID)
+	if err != nil {
+		http.Error(w, `{"error":"failed to list participants"}`, http.StatusInternalServerError)
+		return
+	}
+
+	type participantInfo struct {
+		Identity string `json:"identity"`
+		State    string `json:"state"`
+	}
+
+	result := make([]participantInfo, 0, len(participants))
+	for _, p := range participants {
+		state := "connected"
+		if p.State == livekit.ParticipantInfo_DISCONNECTED {
+			state = "disconnected"
+		}
+		result = append(result, participantInfo{
+			Identity: p.Identity,
+			State:    state,
+		})
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(result)
+}