Live view: a Desktop view that stays still, and Control to tap on the Frame (#46)

* Live view: a Desktop view that stays still, and Control to tap on the Frame

The live view gets a second source and a way to use the Frame from it:

- Desktop: the app panel in use in the headset, streamed from its own window
  (x11grab of gamescope's redirected window), so it doesn't move as the
  wearer looks around. A picker shows any other panel, view only.
- Control: on the Desktop view a tap or click lands exactly where you put it;
  drag is a mouse drag, press and hold right-clicks, two fingers scroll, and
  on a computer the mouse, wheel and keyboard work directly. On the headset
  view the view is a trackpad. A text field and key row type from a phone.

Input goes through gamescope's own EIS socket (the way Steam feeds Remote
Play input) with the libei already on the image: ui/frame_touch.py, over
the same long-lived ssh machinery as the keyboard agent, nothing to
install. It reaches the panel that has focus on either X display, which
the KDE Connect route can't. Verified on the Frame and from the iPhone app
in the Simulator.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* Control: fixes from review

- Keys held on the Frame are released with buttons when Control stops or
  the view loses focus; keys for the Frame no longer trigger Frame Control's
  own shortcuts.
- Taps only act when the picture on screen is the panel in use; positions,
  presses, keys, text and scrolls name their panel (display and window: ids
  repeat across :0 and :1, told apart by pid), and the Frame drops them if
  focus has moved on. Releases always go.
- While connecting, a tap keeps its position; on an error only releases wait
  and retries back off; trimming a long queue never drops a release.
- Lifting one of two scrolling fingers ends the scroll; a cancelled touch
  isn't a tap; clicks and holds on the bars around the picture do nothing.
- A capture loop from before a Live restart can't stop the new video.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* Control: close the targeting gaps from the second review

- The focused panel's display comes from GAMESCOPE_FOCUS_DISPLAY (gamescope
  packs ":1" into the first value), so a window id repeated across :0 and :1
  can't be mistaken; the pid is only the fallback.
- Presses, keys, text and scrolls read focus afresh on the Frame; only moves
  use a reading up to a second old.
- A gesture remembers the panel it started on and does nothing more if that
  stops being the one in use; a press with no panel to aim at isn't sent.
- Opening a screenshot clears the panel Control would act on; switching to
  another app releases held keys and buttons.
- Trimming keeps a click with its position; the error backoff holds for new
  input too.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* Control: fixes from the SWE-2 Max review

- The Frame side tracks keys as well as buttons and lets go of both when the
  session ends.
- A stale tap tells the page, which re-reads the panels at once.
- A paused input device waits instead of ending the session; only a
  disconnect does. An OS error on one event skips it.
- Presses check focus with two property reads and do the full lookup only
  when it changed.
- Writes to an agent's stdin are serialized, so two devices sending at once
  can't tear a line (the keyboard agent too).
- Connecting gives up with a message after 15 s instead of hanging on
  "Connecting…"; text goes in 100-character pieces so releases don't wait
  behind a long paste; a cancelled mouse gesture releases what's held.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* Control: stale clears, pauses reconverge, pastes split per request

- The Frame says it has caught up as soon as an aimed event lands after a
  stale one, so the page stops re-reading the panels.
- After a device pause it lets go of everything it holds (releases that
  arrived while paused were dropped), and waits for the device once per
  batch, not once per event.
- The quick focus check no longer freshens the panel geometry's age.
- Each request carries at most about 100 characters of text.
- Turning Control off while it connects doesn't report an error.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* frame_touch: build the socket path on the Frame, so Windows can import it for tests

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* frame_touch: any event that goes through clears the stale flag

A trackpad move names no panel, so waiting for an aimed event could leave
the page re-reading panels for the rest of the session; a release still
aimed at the old panel doesn't count.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/how-the-frame-works.md

@@ -40,6 +40,8 @@ Lepton (Android 11, podman container "lepton-dev") ← its own panel, app 305600
 | Present: `rsync`, `flatpak`, `python3`, `git`, `qdbus6`, `xrdp`, `xprop`, `xwininfo`, `xterm`, `konsole`, `dolphin`, `gamescopectl`. Missing: `wl-copy`, `xclip`, `xsel`, `kdeconnect-cli`, `tailscale` (installable in `~`, see below), `krfb`, `wayvnc`. | Script design |
 | **SteamOS updates arrive on their own.** The Frame went from 0.3.0 (build 20260922.6101926) to **0.4.1, build 20260925.6191901**, between 2026-09-27 and 2026-09-28 with no action from us; `~` (keys, user Flatpaks, `~/.local/share`) survived. **Verified 2026-09-28.** | Keep changes in `~` |
 | **Valve's package repository has more than the image.** `pacman -Si` / `pacman -Sp` work as `steamos` without root and list Valve's own builds, such as `kdeconnect` 24.02.2 and `python-evdev` 1.7.0 in `extra`. Unpacking those packages into `~` runs them without touching the read-only root. The repository URLs say not to share them, so never write them down; Valve also publishes each build's source package there (`sources/packages/`), which is how Frame Control got the complete source for the KDE Connect it ships. **Verified 2026-09-28**, SteamOS 0.4.1. | [streaming.md](streaming.md#input-type-and-point-in-the-frame-from-the-mac-or-iphone) |
+| **gamescope has its own input injection.** An EIS socket at `/run/user/1000/gamescope-0-ei` (libei 1.4.1 is on the image) offers "Gamescope Virtual Input": relative and absolute pointer, buttons, scroll, keyboard. It drives the panel that has focus in the headset, on either X display. Focus moves only with the controller's laser (or to a new panel when none has it); `gamescopectl focus_info` prints the focus state to the journal. **Verified 2026-09-29.** | [streaming.md](streaming.md#live-view-and-control-watch-a-panel-and-tap-on-it) |
+| **A panel's own pixels:** `ffmpeg -f x11grab -window_id <window> -i :<display>` captures one window (x11grab of the root is black under gamescope). Panels live on `:0` (Steam's UI, windows tagged by `panel-on-frame.sh`) or `:1` (apps Steam starts). **Verified 2026-09-29.** | Frame Control's Desktop view |
 | **gamescope runs two Xwayland displays.** `:0` holds Steam's VR bar and menus (`valve.steam.gamepadui.*`) and ignores XTest pointer motion; `:1` holds apps such as Chromium and takes it. There's also a libei socket, `/run/user/1000/gamescope-0-ei`. **Verified 2026-09-28**, SteamOS 0.4.1. | Keyboard and trackpad |
 | Flathub is a **system** remote. `--user` installs over SSH work and show up in the desktop menu. | `install-apps.sh` |
 | `/` is 10 GB and read-only. `/home` is 929 GB. | Where to put things |