add: show metadata, streams, and clock-time ETA in status UI

Surface the fetched job metadata (show/episode or movie title, season,
episode, release/airdate, media type) and the source audio/subtitle streams
through the tracker and /status, and render them in the dashboard's current-job
card. Audio channel counts are now probed and shown as 5.1/2.0/etc.

ETA now reads as a wall-clock finish time plus remaining duration, e.g.
"17:49 (3h52m)". Recent events drop the per-row date for a WhatsApp-style
Today/Yesterday/date divider with time-only rows. All dynamic strings are
HTML-escaped, since metadata and filenames are user-controlled.

internal/status/status.go

@@ -20,12 +20,34 @@ const (
 	PhaseEncoding = "encoding"
 )
 
+// JobMeta is the fetched metadata for the active job, shaped for display.
+type JobMeta struct {
+	IsSeries     bool   `json:"is_series"`
+	Title        string `json:"title"`                // movie title or episode title
+	Collection   string `json:"collection,omitempty"` // show name (series)
+	Season       string `json:"season,omitempty"`
+	Episode      string `json:"episode,omitempty"`
+	DateReleased string `json:"date_released,omitempty"` // release date / airdate
+	MediaType    string `json:"media_type,omitempty"`
+}
+
+// Stream is one source audio or subtitle stream, for display.
+type Stream struct {
+	Kind     string `json:"kind"` // "audio" | "subtitle"
+	Language string `json:"language,omitempty"`
+	Codec    string `json:"codec,omitempty"`
+	Channels int    `json:"channels,omitempty"` // audio only
+	Title    string `json:"title,omitempty"`
+}
+
 // Tracker holds live progress for the active job. Safe for concurrent use:
 // the encode goroutine writes, HTTP/log readers call Snapshot.
 type Tracker struct {
 	mu        sync.RWMutex
 	file      string
 	phase     string
+	meta      *JobMeta
+	streams   []Stream
 	totalSec  float64 // source duration; 0 until known
 	outTime   float64 // encoded position in seconds
 	fps       float64
@@ -37,6 +59,8 @@ type Tracker struct {
 type Snapshot struct {
 	File       string    `json:"file"`
 	Phase      string    `json:"phase"`
+	Meta       *JobMeta  `json:"meta"`
+	Streams    []Stream  `json:"streams"`
 	Percent    float64   `json:"percent"`
 	FPS        float64   `json:"fps"`
 	Speed      float64   `json:"speed"`
@@ -55,6 +79,8 @@ func (t *Tracker) Begin(file string) {
 	defer t.mu.Unlock()
 	t.file = file
 	t.phase = PhaseProbing
+	t.meta = nil
+	t.streams = nil
 	t.totalSec, t.outTime, t.fps, t.speed = 0, 0, 0, 0
 	t.startedAt = time.Now()
 }
@@ -65,6 +91,20 @@ func (t *Tracker) SetPhase(p string) {
 	t.phase = p
 }
 
+// SetMeta records the fetched metadata for the active job.
+func (t *Tracker) SetMeta(m JobMeta) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.meta = &m
+}
+
+// SetStreams records the source audio/subtitle streams for the active job.
+func (t *Tracker) SetStreams(s []Stream) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.streams = s
+}
+
 // SetTotal records the source duration in seconds (from ffprobe).
 func (t *Tracker) SetTotal(seconds float64) {
 	t.mu.Lock()
@@ -85,6 +125,8 @@ func (t *Tracker) Idle() {
 	defer t.mu.Unlock()
 	t.file = ""
 	t.phase = PhaseIdle
+	t.meta = nil
+	t.streams = nil
 	t.totalSec, t.outTime, t.fps, t.speed = 0, 0, 0, 0
 	t.startedAt = time.Time{}
 }
@@ -95,6 +137,8 @@ func (t *Tracker) Snapshot() Snapshot {
 	s := Snapshot{
 		File:      t.file,
 		Phase:     t.phase,
+		Meta:      t.meta,
+		Streams:   t.streams,
 		FPS:       t.fps,
 		Speed:     t.speed,
 		StartedAt: t.startedAt,