Default overlay to enabled in HTML mode

Fresh installs now show the overlay over the live picture in the web
UI without any server-side overlay processing. Previously the overlay
defaulted to off entirely.

The change is just to loadState()'s default values; both fields are
still read from the state file when present, so existing users who
have explicitly toggled either setting keep their preference. Users
upgrading from before overlay_baked existed get the new HTML default
(was implicitly baked before).

Behavior with the new defaults on a fresh install:
- Master overlay: on
- Overlay type: HTML (baked off)
- runOverlay() drops frames without decoding (no CPU overhead)
- /stream/overlay and /snapshot/overlay return 503 (HTML mode)
- RTSP overlay process does not start
- Web UI shows stats overlaid via CSS on top of the raw stream

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -25,12 +25,14 @@ RTSP feeds can be toggled on/off at runtime from the web UI without restarting t
 
 The **raw HTTP stream and snapshot** (`/stream/raw`, `/snapshot/raw`, and the mjpg_streamer-compatible `/webcam/?action=stream` and `/webcam/?action=snapshot`) are always available, regardless of any runtime toggle. They never carry the overlay. Point OctoPrint's Classic Webcam plugin at these URLs for reliable live feeds and snapshot capture.
 
-The **overlay feed** is a separate master toggle (rendering, MJPEG, RTSP). It defaults to **off** so a fresh install serves only the raw feed and consumes no CPU for the overlay. The RTSP overlay sub-toggle is preserved across master toggles but the ffmpeg process only runs when both are on.
+The **overlay feed** is a separate master toggle (rendering, MJPEG, RTSP). It defaults to **on** in **HTML** mode, so a fresh install shows the stats over the live picture in the web UI without doing any server-side JPEG decode/draw/encode. The RTSP overlay sub-toggle is preserved across master toggles but the ffmpeg process only runs when the master is on **and** the overlay type is baked.
 
 **Overlay type** can be switched at runtime between two modes:
 
-- **Baked**: the overlay is rendered server-side and burned into the JPEG frames. Works with OctoPrint, VLC, and any RTSP consumer. Higher CPU cost.
-- **HTML**: the overlay is drawn client-side over the raw stream. No JPEG decode/draw/encode on the server. Web-only — `/stream/overlay` and `/snapshot/overlay` return 503 and the RTSP overlay process is stopped.
+- **HTML** (default): the overlay is drawn client-side over the raw stream. No JPEG decode/draw/encode on the server. Web-only — `/stream/overlay` and `/snapshot/overlay` return 503 and the RTSP overlay process is stopped.
+- **Baked**: the overlay is rendered server-side and burned into the JPEG frames. Required for OctoPrint, VLC, or any consumer that expects the stats inside the video stream. Higher CPU cost.
+
+All toggles — master overlay, overlay type, and both RTSP feed states — persist in the state file (`/var/lib/octocam/feeds.json` by default) and survive reboots.
 
 ## Architecture
 

internal/pipeline/pipeline.go

@@ -126,8 +126,10 @@ type pipelineState struct {
 }
 
 func (p *Pipeline) loadState() pipelineState {
-	// Default: overlay off, baked overlay if enabled, both RTSP feeds off.
-	state := pipelineState{OverlayBaked: true}
+	// Defaults on first run: overlay enabled in HTML mode (no server-side
+	// JPEG decode/draw/encode), both RTSP feeds off. The state file overrides
+	// any field it specifies, so toggles set by the user persist across reboots.
+	state := pipelineState{OverlayEnabled: true}
 	data, err := os.ReadFile(p.cfg.StateFile)
 	if err != nil {
 		return state // file absent = first run, use defaults