Per-tile stream quality (high/low), fps cap, latency flags

Cameras carry multiple stream URLs (streams: high/medium/low); each
tile picks one via Quality (auto/high/low). Small tiles can pull the
low substream to cut Pi decode load. discover --enable-rtsp takes a
comma list (high,low), enables each channel, records all enabled ones.
TUI: q cycles a tile quality (shown in the tile); discover enables
high+low. Player: --framedrop + low-delay demuxer flags; player.max_fps.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/tui/gridedit.go

@@ -96,6 +96,8 @@ func (m *model) updateLayoutEdit(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		m.screen, m.cursor = screenCameraPicker, 0
 	case "c":
 		m.clearAt()
+	case "q": // cycle this tile's stream quality (high/low/auto)
+		m.cycleQuality()
 	case "L": // grow wider (toward the right)
 		m.resizeTile(1, 0)
 	case "H": // shrink narrower (from the right)
@@ -149,6 +151,36 @@ func (m *model) clearAt() {
 	}
 }
 
+// cycleQuality steps the tile under the cursor through auto → its camera's
+// available stream qualities (high/low/...). Small tiles → pick low; big tiles
+// → high, to keep the Pi's decode load down.
+func (m *model) cycleQuality() {
+	idx := m.tileIndexAt(m.edCol, m.edRow)
+	if idx < 0 {
+		m.setStatus("no tile here — assign a camera first", true)
+		return
+	}
+	t := &m.curLayout().Tiles[idx]
+	opts := []string{""} // "" = auto (best available)
+	if cam := m.cfg.CameraByName(t.Camera); cam != nil {
+		opts = append(opts, cam.AvailableQualities()...)
+	}
+	cur := 0
+	for i, q := range opts {
+		if q == t.Quality {
+			cur = i
+			break
+		}
+	}
+	t.Quality = opts[(cur+1)%len(opts)]
+	m.dirty = true
+	label := t.Quality
+	if label == "" {
+		label = "auto"
+	}
+	m.setStatus("tile quality: "+label, false)
+}
+
 // resizeTile grows/shrinks the tile under the cursor by the given span deltas,
 // keeping it in-bounds and non-overlapping.
 func (m *model) resizeTile(dCol, dRow int) {