feat(live): add web track map (#32)

Subscribe to SignalR Position.z and CarData.z, decode DEFLATE payloads, stream throttled positions over SSE, and render live car dots against cached track outline bounds with tap telemetry.

Alignment spike: no checked-in or locally cached real Position.z samples were available in this isolated worktree; verified both streams expose the official raw F1 X/Y/Z coordinate contract and implemented shared-bounds normalization against prefetched OpenF1 outlines. Fallback build-outline-from-stream was not taken.

Playwright remains out of scope for live rendering because BOXBOX_DISABLE_LIVE is used there; coverage is via parser, web handler/SSE, pure transform, and seeded component tests.

internal/live/parser_test.go

@@ -1,6 +1,9 @@
 package live_test
 
 import (
+	"bytes"
+	"compress/flate"
+	"encoding/base64"
 	"encoding/json"
 	"testing"
 	"time"
@@ -158,6 +161,64 @@ func TestProcessTopicTimingData(t *testing.T) {
 	}
 }
 
+func TestProcessTopicCompressedPositionAndCarData(t *testing.T) {
+	state := live.NewState()
+	positionPayload := `{
+		"Position": [
+			{"Timestamp": "2026-07-03T14:00:00Z", "Entries": {
+				"1": {"Status": "OnTrack", "X": 1000, "Y": -200, "Z": 3},
+				"44": {"Status": "OffTrack", "X": 1200, "Y": -250, "Z": 2}
+			}}
+		]
+	}`
+	if !state.ProcessTopic("Position.z", encodedDeflatePayload(t, positionPayload)) {
+		t.Fatal("Position.z should update state")
+	}
+
+	snap := state.Snapshot()
+	if !snap.PositionUpdated || snap.SnapshotUpdated {
+		t.Fatalf("position flags = position:%v snapshot:%v", snap.PositionUpdated, snap.SnapshotUpdated)
+	}
+	if got := snap.Positions["1"]; got.X != 1000 || got.Y != -200 || got.Z != 3 || got.Status != "OnTrack" {
+		t.Fatalf("position 1 = %+v", got)
+	}
+	if got := snap.Positions["44"]; got.Status != "OffTrack" {
+		t.Fatalf("position 44 = %+v", got)
+	}
+
+	carPayload := `{
+		"Entries": [
+			{"Utc": "2026-07-03T14:00:00Z", "Cars": {
+				"1": {"Channels": {"0": 11234, "2": 318, "3": 8, "4": 92, "5": 0, "45": 10}}
+			}}
+		]
+	}`
+	if !state.ProcessTopic("CarData.z", encodedDeflatePayload(t, carPayload)) {
+		t.Fatal("CarData.z should update state")
+	}
+	snap = state.Snapshot()
+	if !snap.SnapshotUpdated {
+		t.Fatal("CarData should mark snapshot updated")
+	}
+	tel := snap.Telemetry["1"]
+	if tel.RPM != 11234 || tel.Speed != 318 || tel.NGear != 8 || tel.Throttle != 92 || tel.Brake != 0 || tel.DRS != 10 {
+		t.Fatalf("telemetry = %+v", tel)
+	}
+}
+
+func TestProcessTopicSessionInfoCircuitName(t *testing.T) {
+	state := live.NewState()
+	state.ProcessTopic("SessionInfo", json.RawMessage(`{
+		"Meeting": {"Name": "British Grand Prix", "Circuit": {"ShortName": "Silverstone"}},
+		"Name": "Race",
+		"Type": "Race"
+	}`))
+	s := state.Snapshot().Session
+	if s.MeetingName != "British Grand Prix" || s.CircuitName != "Silverstone" {
+		t.Fatalf("session = %+v", s)
+	}
+}
+
 func TestProcessTopicDriverList(t *testing.T) {
 	state := live.NewState()
 	data := json.RawMessage(`{"63": {"RacingNumber": "63", "Tla": "RUS", "TeamName": "Mercedes", "TeamColour": "27F4D2"}}`)
@@ -356,3 +417,23 @@ func TestProcessMessageEmptyPayload(t *testing.T) {
 		t.Error("empty envelope should not update state")
 	}
 }
+
+func encodedDeflatePayload(t *testing.T, payload string) json.RawMessage {
+	t.Helper()
+	var buf bytes.Buffer
+	w, err := flate.NewWriter(&buf, flate.DefaultCompression)
+	if err != nil {
+		t.Fatalf("flate.NewWriter() error = %v", err)
+	}
+	if _, err := w.Write([]byte(payload)); err != nil {
+		t.Fatalf("flate write error = %v", err)
+	}
+	if err := w.Close(); err != nil {
+		t.Fatalf("flate close error = %v", err)
+	}
+	raw, err := json.Marshal(base64.StdEncoding.EncodeToString(buf.Bytes()))
+	if err != nil {
+		t.Fatalf("marshal payload error = %v", err)
+	}
+	return raw
+}

internal/live/signalr.go

@@ -96,6 +96,8 @@ func connectToF1SignalRCore(dataChan chan LiveStreamData) error {
 	topics := []string{
 		"Heartbeat",
 		"TimingData",
+		"Position.z",
+		"CarData.z",
 		"DriverList",
 		"LapCount",
 		"ExtrapolatedClock",
@@ -194,7 +196,7 @@ func connectToF1LegacySignalR(dataChan chan LiveStreamData) error {
 		return err
 	}
 
-	subscribeMsg := []byte(`{"H":"Streaming","M":"Subscribe","A":[["Heartbeat","TimingData","DriverList","LapCount","ExtrapolatedClock","TrackStatus","RaceControlMessages","WeatherData","SessionInfo","CurrentTyres","TimingAppData","TimingStats"]],"I":1}`)
+	subscribeMsg := []byte(`{"H":"Streaming","M":"Subscribe","A":[["Heartbeat","TimingData","Position.z","CarData.z","DriverList","LapCount","ExtrapolatedClock","TrackStatus","RaceControlMessages","WeatherData","SessionInfo","CurrentTyres","TimingAppData","TimingStats"]],"I":1}`)
 	err = c.WriteMessage(websocket.TextMessage, subscribeMsg)
 	if err != nil {
 		return err

internal/live/state.go

@@ -1,8 +1,14 @@
 package live
 
 import (
+	"bytes"
+	"compress/flate"
+	"compress/zlib"
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
+	"io"
+	"strings"
 	"time"
 )
 
@@ -11,6 +17,8 @@ type State struct {
 	Drivers            map[string]LiveDriverData
 	DriverInfo         map[string]F1DriverListEntry
 	Tyres              map[string]LiveTyreData
+	Telemetry          map[string]LiveTelemetryData
+	Positions          map[string]LivePositionData
 	Stints             map[string][]LiveStintData
 	RCMessages         []LiveRCMessage
 	Weather            LiveWeatherData
@@ -21,6 +29,8 @@ type State struct {
 	Clock              string
 	ClockRefTime       time.Time
 	ClockExtrapolating bool
+	positionUpdated    bool
+	snapshotUpdated    bool
 }
 
 const signalRRecordSeparator = byte(0x1e)
@@ -31,6 +41,8 @@ func NewState() *State {
 		Drivers:    make(map[string]LiveDriverData),
 		DriverInfo: make(map[string]F1DriverListEntry),
 		Tyres:      make(map[string]LiveTyreData),
+		Telemetry:  make(map[string]LiveTelemetryData),
+		Positions:  make(map[string]LivePositionData),
 		Stints:     make(map[string][]LiveStintData),
 	}
 }
@@ -49,6 +61,14 @@ func (s *State) Snapshot() LiveStreamData {
 	for k, v := range s.Tyres {
 		cpyTyres[k] = v
 	}
+	cpyTelemetry := make(map[string]LiveTelemetryData, len(s.Telemetry))
+	for k, v := range s.Telemetry {
+		cpyTelemetry[k] = v
+	}
+	cpyPositions := make(map[string]LivePositionData, len(s.Positions))
+	for k, v := range s.Positions {
+		cpyPositions[k] = v
+	}
 	cpyRC := make([]LiveRCMessage, len(s.RCMessages))
 	copy(cpyRC, s.RCMessages)
 	cpyStints := make(map[string][]LiveStintData, len(s.Stints))
@@ -62,6 +82,7 @@ func (s *State) Snapshot() LiveStreamData {
 		Drivers:            cpyDrivers,
 		DriverInfo:         cpyInfo,
 		Tyres:              cpyTyres,
+		Telemetry:          cpyTelemetry,
 		RCMessages:         cpyRC,
 		Weather:            s.Weather,
 		Session:            s.Session,
@@ -72,11 +93,16 @@ func (s *State) Snapshot() LiveStreamData {
 		ClockRefTime:       s.ClockRefTime,
 		ClockExtrapolating: s.ClockExtrapolating,
 		Stints:             cpyStints,
+		Positions:          cpyPositions,
+		PositionUpdated:    s.positionUpdated,
+		SnapshotUpdated:    s.snapshotUpdated,
 	}
 }
 
 // ProcessMessage parses a raw SignalR WebSocket frame and applies any updates.
 func (s *State) ProcessMessage(message []byte) bool {
+	s.clearTransientFlags()
+
 	var parsed F1SignalRMessage
 	if err := json.Unmarshal(message, &parsed); err != nil {
 		return false
@@ -111,6 +137,8 @@ func (s *State) ProcessMessage(message []byte) bool {
 // ProcessCoreMessage parses one or more SignalR Core JSON frames and applies
 // completion snapshots and feed deltas from the current official F1 live timing hub.
 func (s *State) ProcessCoreMessage(message []byte) bool {
+	s.clearTransientFlags()
+
 	updated := false
 	for _, frame := range splitSignalRFrames(message) {
 		var envelope struct {
@@ -156,7 +184,15 @@ func (s *State) ProcessCoreMessage(message []byte) bool {
 // ProcessTopic applies a single topic payload to the accumulator.
 func (s *State) ProcessTopic(topic string, data json.RawMessage) bool {
 	updated := false
-	switch topic {
+	baseTopic := strings.TrimSuffix(topic, ".z")
+	if topic != baseTopic {
+		var ok bool
+		data, ok = inflateTopicPayload(data)
+		if !ok {
+			return false
+		}
+	}
+	switch baseTopic {
 	case "TimingData":
 		var td struct {
 			Lines map[string]json.RawMessage `json:"Lines"`
@@ -170,6 +206,10 @@ func (s *State) ProcessTopic(topic string, data json.RawMessage) bool {
 				}
 			}
 		}
+	case "Position":
+		updated = s.updatePositions(data)
+	case "CarData":
+		updated = s.updateTelemetry(data)
 	case "DriverList":
 		var dlMap map[string]json.RawMessage
 		if json.Unmarshal(data, &dlMap) == nil {
@@ -288,7 +328,10 @@ func (s *State) ProcessTopic(topic string, data json.RawMessage) bool {
 	case "SessionInfo":
 		var si struct {
 			Meeting struct {
-				Name string `json:"Name"`
+				Name    string `json:"Name"`
+				Circuit struct {
+					ShortName string `json:"ShortName"`
+				} `json:"Circuit"`
 			} `json:"Meeting"`
 			Name string `json:"Name"`
 			Type string `json:"Type"`
@@ -297,6 +340,9 @@ func (s *State) ProcessTopic(topic string, data json.RawMessage) bool {
 			if si.Meeting.Name != "" {
 				s.Session.MeetingName = si.Meeting.Name
 			}
+			if si.Meeting.Circuit.ShortName != "" {
+				s.Session.CircuitName = si.Meeting.Circuit.ShortName
+			}
 			if si.Name != "" {
 				s.Session.SessionName = si.Name
 			}
@@ -386,9 +432,177 @@ func (s *State) ProcessTopic(topic string, data json.RawMessage) bool {
 			}
 		}
 	}
+	if updated {
+		if baseTopic == "Position" {
+			s.positionUpdated = true
+		} else {
+			s.snapshotUpdated = true
+		}
+	}
 	return updated
 }
 
+func (s *State) clearTransientFlags() {
+	s.positionUpdated = false
+	s.snapshotUpdated = false
+}
+
+func inflateTopicPayload(data json.RawMessage) (json.RawMessage, bool) {
+	var encoded string
+	if err := json.Unmarshal(data, &encoded); err != nil {
+		var wrapper struct {
+			Z string `json:"z"`
+		}
+		if json.Unmarshal(data, &wrapper) != nil || wrapper.Z == "" {
+			return nil, false
+		}
+		encoded = wrapper.Z
+	}
+
+	compressed, err := base64.StdEncoding.DecodeString(encoded)
+	if err != nil {
+		return nil, false
+	}
+	if inflated, ok := readCompressed(zlib.NewReader(bytes.NewReader(compressed))); ok {
+		return json.RawMessage(inflated), true
+	}
+	if inflated, ok := readCompressed(func() (io.ReadCloser, error) {
+		return flate.NewReader(bytes.NewReader(compressed)), nil
+	}()); ok {
+		return json.RawMessage(inflated), true
+	}
+	return nil, false
+}
+
+func readCompressed(r io.ReadCloser, err error) ([]byte, bool) {
+	if err != nil {
+		return nil, false
+	}
+	defer r.Close()
+	out, err := io.ReadAll(r)
+	return out, err == nil
+}
+
+func (s *State) updatePositions(data json.RawMessage) bool {
+	var payload struct {
+		Position json.RawMessage `json:"Position"`
+	}
+	if json.Unmarshal(data, &payload) != nil || len(payload.Position) == 0 {
+		return false
+	}
+
+	updated := false
+	for _, sampleRaw := range indexedRawValues(payload.Position) {
+		var sample struct {
+			Entries map[string]struct {
+				Status string      `json:"Status"`
+				X      json.Number `json:"X"`
+				Y      json.Number `json:"Y"`
+				Z      json.Number `json:"Z"`
+			} `json:"Entries"`
+		}
+		if json.Unmarshal(sampleRaw.Raw, &sample) != nil {
+			continue
+		}
+		for num, entry := range sample.Entries {
+			x, okX := numberToFloat(entry.X)
+			y, okY := numberToFloat(entry.Y)
+			z, okZ := numberToFloat(entry.Z)
+			if !okX || !okY {
+				continue
+			}
+			if !okZ {
+				z = 0
+			}
+			s.Positions[num] = LivePositionData{
+				X:      x,
+				Y:      y,
+				Z:      z,
+				Status: entry.Status,
+			}
+			updated = true
+		}
+	}
+	return updated
+}
+
+func (s *State) updateTelemetry(data json.RawMessage) bool {
+	var payload struct {
+		Entries json.RawMessage `json:"Entries"`
+	}
+	if json.Unmarshal(data, &payload) != nil || len(payload.Entries) == 0 {
+		return false
+	}
+
+	updated := false
+	for _, entryRaw := range indexedRawValues(payload.Entries) {
+		var entry struct {
+			Cars map[string]struct {
+				Channels map[string]json.RawMessage `json:"Channels"`
+			} `json:"Cars"`
+		}
+		if json.Unmarshal(entryRaw.Raw, &entry) != nil {
+			continue
+		}
+		for num, car := range entry.Cars {
+			t := s.Telemetry[num]
+			if v, ok := channelInt(car.Channels, "0"); ok {
+				t.RPM = v
+			}
+			if v, ok := channelInt(car.Channels, "2"); ok {
+				t.Speed = v
+			}
+			if v, ok := channelInt(car.Channels, "3"); ok {
+				t.NGear = v
+			}
+			if v, ok := channelInt(car.Channels, "4"); ok {
+				t.Throttle = v
+			}
+			if v, ok := channelInt(car.Channels, "5"); ok {
+				t.Brake = v
+			}
+			if v, ok := channelInt(car.Channels, "45"); ok {
+				t.DRS = v
+			}
+			s.Telemetry[num] = t
+			updated = true
+		}
+	}
+	return updated
+}
+
+func channelInt(channels map[string]json.RawMessage, key string) (int, bool) {
+	raw, ok := channels[key]
+	if !ok {
+		return 0, false
+	}
+	var n json.Number
+	if json.Unmarshal(raw, &n) == nil {
+		if i, err := n.Int64(); err == nil {
+			return int(i), true
+		}
+		if f, err := n.Float64(); err == nil {
+			return int(f), true
+		}
+	}
+	var s string
+	if json.Unmarshal(raw, &s) == nil {
+		var i int
+		if _, err := fmt.Sscanf(s, "%d", &i); err == nil {
+			return i, true
+		}
+	}
+	return 0, false
+}
+
+func numberToFloat(n json.Number) (float64, bool) {
+	if n == "" {
+		return 0, false
+	}
+	v, err := n.Float64()
+	return v, err == nil
+}
+
 func updateDriver(drivers map[string]LiveDriverData, num string, line F1TimingLine) {
 	d, exists := drivers[num]
 	if !exists {

internal/live/types.go

@@ -87,6 +87,24 @@ type LiveSessionMeta struct {
 	SessionName string
 }
 
+// LivePositionData is the latest raw F1 GPS position for one driver.
+type LivePositionData struct {
+	X      float64 `json:"x"`
+	Y      float64 `json:"y"`
+	Z      float64 `json:"z"`
+	Status string  `json:"status"`
+}
+
+// LiveTelemetryData is the latest car telemetry for one driver.
+type LiveTelemetryData struct {
+	Speed    int `json:"Speed"`
+	Throttle int `json:"Throttle"`
+	Brake    int `json:"Brake"`
+	DRS      int `json:"DRS"`
+	NGear    int `json:"NGear"`
+	RPM      int `json:"RPM"`
+}
+
 // LiveSectorData holds a single sector time and flags.
 type LiveSectorData struct {
 	Value           string
@@ -131,6 +149,7 @@ type LiveStreamData struct {
 	Drivers            map[string]LiveDriverData
 	DriverInfo         map[string]F1DriverListEntry
 	Tyres              map[string]LiveTyreData
+	Telemetry          map[string]LiveTelemetryData
 	RCMessages         []LiveRCMessage
 	Weather            LiveWeatherData
 	Session            LiveSessionMeta
@@ -141,4 +160,7 @@ type LiveStreamData struct {
 	ClockRefTime       time.Time // UTC when Clock was accurate
 	ClockExtrapolating bool      // true = actively counting down
 	Stints             map[string][]LiveStintData
+	Positions          map[string]LivePositionData `json:"-"`
+	PositionUpdated    bool                        `json:"-"`
+	SnapshotUpdated    bool                        `json:"-"`
 }

internal/web/api.go

@@ -1046,21 +1046,35 @@ type trackPoint struct {
 	Y float64 `json:"y"`
 }
 
+type trackBounds struct {
+	MinX float64 `json:"minX"`
+	MaxX float64 `json:"maxX"`
+	MinY float64 `json:"minY"`
+	MaxY float64 `json:"maxY"`
+}
+
 type trackOutlineResponse struct {
 	CircuitKey int          `json:"circuit_key"`
 	Points     []trackPoint `json:"points"`
+	Bounds     trackBounds  `json:"bounds"`
 }
 
 func (s *Server) handleTrackOutline(w http.ResponseWriter, r *http.Request) {
-	circuitKey, err := strconv.Atoi(r.URL.Query().Get("circuit_key"))
-	if err != nil || circuitKey == 0 {
-		http.Error(w, "circuit_key required", http.StatusBadRequest)
-		return
-	}
 	year, _ := strconv.Atoi(r.URL.Query().Get("year"))
 	if year == 0 {
 		year = time.Now().Year()
 	}
+	circuitKey, err := strconv.Atoi(r.URL.Query().Get("circuit_key"))
+	if err != nil {
+		circuitKey = 0
+	}
+	if circuitKey == 0 {
+		circuitKey = s.resolveCircuitKey(year, r.URL.Query().Get("meeting_name"), r.URL.Query().Get("circuit_name"))
+	}
+	if circuitKey == 0 {
+		http.Error(w, "circuit_key or live meeting identity required", http.StatusBadRequest)
+		return
+	}
 
 	locs, ok := s.client.Cache().GetTrackOutline(circuitKey, year)
 	if !ok || len(locs) == 0 {
@@ -1110,7 +1124,85 @@ func (s *Server) handleTrackOutline(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	writeJSON(w, trackOutlineResponse{CircuitKey: circuitKey, Points: points})
+	writeJSON(w, trackOutlineResponse{
+		CircuitKey: circuitKey,
+		Points:     points,
+		Bounds:     trackBounds{MinX: minX, MaxX: maxX, MinY: minY, MaxY: maxY},
+	})
+}
+
+func (s *Server) resolveCircuitKey(year int, meetingName, circuitName string) int {
+	if !s.hasLocalQuery() {
+		return 0
+	}
+	meetings, err := s.query.ListMeetingsByYear(year)
+	if err != nil {
+		return 0
+	}
+	wantMeeting := normalizeTrackIdentity(meetingName)
+	wantCircuit := normalizeTrackIdentity(circuitName)
+	bestScore := 0
+	bestCircuitKey := 0
+	for _, m := range meetings {
+		if m.CircuitKey == 0 {
+			continue
+		}
+		score := identityScore(wantMeeting, m.MeetingName, m.MeetingOfficialName, m.Location)
+		score += identityScore(wantCircuit, m.CircuitShortName, m.Location, m.MeetingName)
+		if score > bestScore {
+			bestScore = score
+			bestCircuitKey = m.CircuitKey
+		}
+	}
+	if bestScore == 0 {
+		return 0
+	}
+	return bestCircuitKey
+}
+
+func identityScore(want string, candidates ...string) int {
+	if want == "" {
+		return 0
+	}
+	best := 0
+	for _, candidate := range candidates {
+		got := normalizeTrackIdentity(candidate)
+		if got == "" {
+			continue
+		}
+		switch {
+		case got == want:
+			if best < 4 {
+				best = 4
+			}
+		case strings.Contains(got, want) || strings.Contains(want, got):
+			if best < 2 {
+				best = 2
+			}
+		}
+	}
+	return best
+}
+
+func normalizeTrackIdentity(s string) string {
+	s = strings.ToLower(s)
+	replacer := strings.NewReplacer(
+		"grand prix", "",
+		" gp", "",
+		"circuit", "",
+		"autodromo", "",
+		"autódromo", "",
+		"international", "",
+		"street", "",
+		" ", "",
+		"-", "",
+		"_", "",
+		".", "",
+		",", "",
+		"'", "",
+		"’", "",
+	)
+	return strings.TrimSpace(replacer.Replace(s))
 }
 
 // --- /api/v1/strategy ---

internal/web/live.go

@@ -29,9 +29,10 @@ type SSEHub struct {
 	deregister chan *sseClient
 	broadcast  chan sseEvent
 
-	mu           sync.RWMutex
-	lastSnapshot *live.LiveStreamData
-	isLive       bool
+	mu            sync.RWMutex
+	lastSnapshot  *live.LiveStreamData
+	lastPositions map[string]live.LivePositionData
+	isLive        bool
 }
 
 func newSSEHub() *SSEHub {
@@ -52,6 +53,7 @@ func (h *SSEHub) run() {
 			// Send catch-up snapshot so new clients see current state immediately.
 			h.mu.RLock()
 			snap := h.lastSnapshot
+			positions := cloneLivePositions(h.lastPositions)
 			live := h.isLive
 			h.mu.RUnlock()
 			if snap != nil {
@@ -62,6 +64,14 @@ func (h *SSEHub) run() {
 					}
 				}
 			}
+			if len(positions) > 0 {
+				if data, err := json.Marshal(positions); err == nil {
+					select {
+					case c.ch <- formatSSEFrame("positions", data):
+					default:
+					}
+				}
+			}
 
 		case c := <-h.deregister:
 			if clients[c] {
@@ -122,6 +132,7 @@ func (s *Server) signalRLoop() {
 		s.hub.mu.Lock()
 		s.hub.isLive = false
 		s.hub.lastSnapshot = nil
+		s.hub.lastPositions = nil
 		s.hub.mu.Unlock()
 
 		if payload, err := json.Marshal(map[string]any{"data": nil, "is_live": false}); err == nil {
@@ -150,17 +161,33 @@ func (s *Server) connectAndDrain() error {
 	idleTimeout := 60 * time.Second
 	timer := time.NewTimer(idleTimeout)
 	defer timer.Stop()
+	lastPositionBroadcast := time.Time{}
 
 	for {
 		select {
 		case data := <-dataChan:
+			now := time.Now()
 			s.hub.mu.Lock()
-			s.hub.lastSnapshot = &data
+			if data.SnapshotUpdated {
+				s.hub.lastSnapshot = &data
+			}
+			if data.PositionUpdated && len(data.Positions) > 0 {
+				s.hub.lastPositions = cloneLivePositions(data.Positions)
+			}
 			s.hub.isLive = true
 			s.hub.mu.Unlock()
 
-			if payload, err := json.Marshal(map[string]any{"data": data, "is_live": true}); err == nil {
-				s.hub.broadcast <- sseEvent{name: "snapshot", data: payload}
+			if data.SnapshotUpdated {
+				if payload, err := json.Marshal(map[string]any{"data": data, "is_live": true}); err == nil {
+					s.hub.broadcast <- sseEvent{name: "snapshot", data: payload}
+				}
+			}
+
+			if data.PositionUpdated && len(data.Positions) > 0 && now.Sub(lastPositionBroadcast) >= 250*time.Millisecond {
+				if payload, err := json.Marshal(data.Positions); err == nil {
+					s.hub.broadcast <- sseEvent{name: "positions", data: payload}
+					lastPositionBroadcast = now
+				}
 			}
 
 			if !timer.Stop() {
@@ -177,6 +204,17 @@ func (s *Server) connectAndDrain() error {
 	}
 }
 
+func cloneLivePositions(in map[string]live.LivePositionData) map[string]live.LivePositionData {
+	if len(in) == 0 {
+		return nil
+	}
+	out := make(map[string]live.LivePositionData, len(in))
+	for k, v := range in {
+		out[k] = v
+	}
+	return out
+}
+
 // handleLiveState returns the current live data snapshot as JSON.
 func (s *Server) handleLiveState(w http.ResponseWriter, r *http.Request) {
 	snap, isLive := s.hub.Snapshot()

internal/web/live_trackmap_test.go

@@ -0,0 +1,76 @@
+package web
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/AmanTahiliani/box-box/internal/live"
+	"github.com/AmanTahiliani/box-box/internal/models"
+	"github.com/AmanTahiliani/box-box/internal/store"
+)
+
+func TestHandleTrackOutlineReturnsBoundsAndResolvesLiveIdentity(t *testing.T) {
+	st := openTestStore(t)
+	if err := st.UpsertMeeting(store.Meeting{
+		MeetingKey:       1234,
+		MeetingName:      "British Grand Prix",
+		Location:         "Silverstone",
+		CircuitKey:       9,
+		CircuitShortName: "Silverstone",
+		Year:             2026,
+	}); err != nil {
+		t.Fatalf("UpsertMeeting() error = %v", err)
+	}
+	srv := testServer(t, st)
+	locs := []models.Location{
+		{X: -100, Y: 50, Z: 0},
+		{X: 0, Y: 100, Z: 0},
+		{X: 100, Y: 50, Z: 0},
+	}
+	if err := srv.client.Cache().SetTrackOutline(9, 2026, locs); err != nil {
+		t.Fatalf("SetTrackOutline() error = %v", err)
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/track-outline?meeting_name=British+Grand+Prix&circuit_name=Silverstone&year=2026", nil)
+	rec := httptest.NewRecorder()
+	srv.handleTrackOutline(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200: %s", rec.Code, rec.Body.String())
+	}
+	var resp trackOutlineResponse
+	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("decode response: %v", err)
+	}
+	if resp.CircuitKey != 9 {
+		t.Fatalf("circuit_key = %d, want 9", resp.CircuitKey)
+	}
+	if resp.Bounds.MinX != -100 || resp.Bounds.MaxX != 100 || resp.Bounds.MinY != 50 || resp.Bounds.MaxY != 100 {
+		t.Fatalf("bounds = %+v", resp.Bounds)
+	}
+	if len(resp.Points) != 3 {
+		t.Fatalf("points len = %d, want 3", len(resp.Points))
+	}
+}
+
+func TestPositionsSSEFrameShape(t *testing.T) {
+	payload, err := json.Marshal(map[string]live.LivePositionData{
+		"1": {X: 100, Y: -50, Z: 2, Status: "OnTrack"},
+	})
+	if err != nil {
+		t.Fatalf("marshal positions: %v", err)
+	}
+	frame := string(formatSSEFrame("positions", payload))
+	if !strings.HasPrefix(frame, "event: positions\ndata: ") {
+		t.Fatalf("frame prefix = %q", frame)
+	}
+	if !strings.Contains(frame, `"1":{"x":100,"y":-50,"z":2,"status":"OnTrack"}`) {
+		t.Fatalf("frame data = %q", frame)
+	}
+	if !strings.HasSuffix(frame, "\n\n") {
+		t.Fatalf("frame should end with blank line: %q", frame)
+	}
+}