feat(bugseti): add HubService types and constructor

Introduce HubService struct with types for hub coordination: PendingOp,
HubClaim, LeaderboardEntry, GlobalStats, ConflictError, NotFoundError.
Constructor generates a crypto/rand client ID when none exists. Includes
no-op loadPendingOps/savePendingOps stubs for future persistence.

Co-Authored-By: Virgil <virgil@lethean.io>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/bugseti/hub.go

@@ -0,0 +1,129 @@
+// Package bugseti provides services for the BugSETI distributed bug fixing application.
+package bugseti
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"net/http"
+	"sync"
+	"time"
+)
+
+// HubService coordinates with the agentic portal for issue assignment and leaderboard.
+type HubService struct {
+	config    *ConfigService
+	client    *http.Client
+	connected bool
+	pending   []PendingOp
+	mu        sync.RWMutex
+}
+
+// PendingOp represents an operation queued for retry when the hub is unreachable.
+type PendingOp struct {
+	Method    string      `json:"method"`
+	Path      string      `json:"path"`
+	Body      interface{} `json:"body,omitempty"`
+	CreatedAt time.Time   `json:"createdAt"`
+}
+
+// HubClaim represents a claimed issue from the hub.
+type HubClaim struct {
+	ID        string    `json:"id"`
+	IssueURL  string    `json:"issueUrl"`
+	ClientID  string    `json:"clientId"`
+	ClaimedAt time.Time `json:"claimedAt"`
+	ExpiresAt time.Time `json:"expiresAt"`
+	Status    string    `json:"status"`
+}
+
+// LeaderboardEntry represents a single entry on the leaderboard.
+type LeaderboardEntry struct {
+	ClientID   string `json:"clientId"`
+	ClientName string `json:"clientName"`
+	Score      int    `json:"score"`
+	PRsMerged  int    `json:"prsMerged"`
+	Rank       int    `json:"rank"`
+}
+
+// GlobalStats holds aggregate statistics from the hub.
+type GlobalStats struct {
+	TotalClients    int `json:"totalClients"`
+	TotalClaims     int `json:"totalClaims"`
+	TotalPRsMerged  int `json:"totalPrsMerged"`
+	ActiveClaims    int `json:"activeClaims"`
+	IssuesAvailable int `json:"issuesAvailable"`
+}
+
+// ConflictError indicates a 409 response from the hub (e.g. issue already claimed).
+type ConflictError struct {
+	StatusCode int
+}
+
+func (e *ConflictError) Error() string {
+	return fmt.Sprintf("conflict: status %d", e.StatusCode)
+}
+
+// NotFoundError indicates a 404 response from the hub.
+type NotFoundError struct {
+	StatusCode int
+}
+
+func (e *NotFoundError) Error() string {
+	return fmt.Sprintf("not found: status %d", e.StatusCode)
+}
+
+// NewHubService creates a new HubService with the given config.
+// If the config has no ClientID, one is generated and persisted.
+func NewHubService(config *ConfigService) *HubService {
+	h := &HubService{
+		config: config,
+		client: &http.Client{
+			Timeout: 10 * time.Second,
+		},
+		pending: make([]PendingOp, 0),
+	}
+
+	// Generate client ID if not set.
+	if config.GetClientID() == "" {
+		id := generateClientID()
+		_ = config.SetClientID(id)
+	}
+
+	h.loadPendingOps()
+
+	return h
+}
+
+// ServiceName returns the service name for Wails.
+func (h *HubService) ServiceName() string {
+	return "HubService"
+}
+
+// GetClientID returns the client ID from config.
+func (h *HubService) GetClientID() string {
+	return h.config.GetClientID()
+}
+
+// IsConnected returns whether the hub was reachable on the last request.
+func (h *HubService) IsConnected() bool {
+	h.mu.RLock()
+	defer h.mu.RUnlock()
+	return h.connected
+}
+
+// generateClientID creates a random hex string (16 bytes = 32 hex chars).
+func generateClientID() string {
+	b := make([]byte, 16)
+	if _, err := rand.Read(b); err != nil {
+		// Fallback: this should never happen with crypto/rand.
+		return fmt.Sprintf("fallback-%d", time.Now().UnixNano())
+	}
+	return hex.EncodeToString(b)
+}
+
+// loadPendingOps is a no-op placeholder (disk persistence comes in Task 7).
+func (h *HubService) loadPendingOps() {}
+
+// savePendingOps is a no-op placeholder (disk persistence comes in Task 7).
+func (h *HubService) savePendingOps() {}

internal/bugseti/hub_test.go

@@ -0,0 +1,48 @@
+package bugseti
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func testHubService(t *testing.T, serverURL string) *HubService {
+	t.Helper()
+	cfg := testConfigService(t, nil, nil)
+	if serverURL != "" {
+		cfg.config.HubURL = serverURL
+	}
+	return NewHubService(cfg)
+}
+
+// ---- NewHubService ----
+
+func TestNewHubService_Good(t *testing.T) {
+	h := testHubService(t, "")
+	require.NotNil(t, h)
+	assert.NotNil(t, h.config)
+	assert.NotNil(t, h.client)
+	assert.False(t, h.IsConnected())
+}
+
+func TestHubServiceName_Good(t *testing.T) {
+	h := testHubService(t, "")
+	assert.Equal(t, "HubService", h.ServiceName())
+}
+
+func TestNewHubService_Good_GeneratesClientID(t *testing.T) {
+	h := testHubService(t, "")
+	id := h.GetClientID()
+	assert.NotEmpty(t, id)
+	// 16 bytes = 32 hex characters
+	assert.Len(t, id, 32)
+}
+
+func TestNewHubService_Good_ReusesClientID(t *testing.T) {
+	cfg := testConfigService(t, nil, nil)
+	cfg.config.ClientID = "existing-client-id"
+
+	h := NewHubService(cfg)
+	assert.Equal(t, "existing-client-id", h.GetClientID())
+}