Document current Frame panel layout API limits

Co-authored-by: SAPHID <saphid@users.noreply.github.com>

CHANGELOG.md

@@ -2,6 +2,19 @@
 
 ## Unreleased
 
+- Recheck saved spatial layouts on SteamOS 0.5.6 / SteamVR 2.18.2 (issue #31).
+  Read-only probes expose some panel geometry, but safe restoration of
+  Steam/gamescope docking and positions remains unverified. Record exact API
+  results and a reproducible probe; saved layouts remain unavailable.
+
+- Record packaged v0.4.17 Desktop Capture succeeding on a mapped nested KDE
+  compositor on a real Frame with SteamOS 0.5.6. Headset overlay visibility was
+  not established; this is evidence, not a new fix or resolution of issue #73.
+
+- Correct the Return to Game Mode help text: Frame Control selects the switch
+  supported by the headset's SteamOS build, including `steamosctl` on current
+  Frames. The button's behavior is unchanged.
+
 - Distinguish an unreadable gamescope panel list from a confirmed empty list in
   Desktop Capture and Control (issue #73). Failed discovery now asks users to
   check SteamVR and report the exact message and SteamOS version, rather than

docs/evidence/desktop-capture-packaged-2026-10-24.json

@@ -0,0 +1,206 @@
+{
+  "date_utc": "2026-10-24",
+  "base_commit": "de931bc",
+  "issue": 73,
+  "result": "Packaged Desktop Capture passed for a mapped nested KDE compositor on the real Frame; wearer-visible overlay condition was not established. Do not close #73 from this test.",
+  "package": {
+    "tag": "v0.4.17",
+    "asset": "Frame-Control-linux-x86_64.AppImage",
+    "sha256": "b1b8eb82bf73a227b2cd36e8f0ef3a2ebdf7967c5853efb08a9634f38227015d",
+    "release_digest_matched": true,
+    "panel_helper_matches_base": true,
+    "unmodified_payload": true,
+    "host": "lxso2",
+    "display": "Xvfb :139",
+    "flags": [
+      "--no-sandbox",
+      "--disable-gpu"
+    ],
+    "private_profile_and_data": true,
+    "telemetry_and_update_checks_disabled": true
+  },
+  "preflight": {
+    "steamos_version": "0.5.6",
+    "build_id": "20261015.6141207",
+    "battery_percent": 99,
+    "battery_status": "Not charging",
+    "game_mode": true,
+    "full_plasma_session": false,
+    "nested_desktop_running": false,
+    "nested_runtime_present": false,
+    "lock_present": false,
+    "steam_pid": 297826,
+    "vrserver_pid": 297506,
+    "vrcompositor_pid": 297620,
+    "gamescope_service_invocation": "e8c1085b3bbd4e79a323b3e4a9bc6355",
+    "focusable_windows": [],
+    "focused_windows": []
+  },
+  "session": {
+    "started_utc": "2026-10-24T09:43:48Z",
+    "lock_acquired": true,
+    "launch": [
+      "systemd-run",
+      "--user",
+      "--unit=fc-issue73-desktop-20261024",
+      "--collect",
+      "--property=RuntimeMaxSec=180s",
+      "--property=TimeoutStopSec=15s",
+      "--property=KillMode=control-group",
+      "--setenv=DISPLAY=:0",
+      "--setenv=XDG_RUNTIME_DIR=/run/user/1000",
+      "--setenv=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus",
+      "--setenv=XDG_SESSION_TYPE=x11",
+      "--setenv=XDG_CURRENT_DESKTOP=gamescope",
+      "/usr/bin/steamos-nested-desktop"
+    ],
+    "response": "Running as unit: fc-issue73-desktop-20261024.service; invocation ID: 92cff1e57c794212997d46c0a68877ec\n"
+  },
+  "discovery": {
+    "focus": 62914560,
+    "focus_display": ":0",
+    "panels": [
+      {
+        "window": 62914560,
+        "display": ":0",
+        "name": "KDE Wayland Compositor - Press right control key to grab input",
+        "x": 0,
+        "y": 0,
+        "width": 1920,
+        "height": 1080,
+        "app": 0,
+        "focused": true
+      }
+    ]
+  },
+  "window_evidence": {
+    "xwininfo_map_state": "IsViewable",
+    "width": 1920,
+    "height": 1080,
+    "focused_after_show_request": true,
+    "steamvr_overlay_key": "valve.steam.desktopgame.0",
+    "steamvr_overlay_visibility_after_show_request": "not_visible"
+  },
+  "capture": {
+    "repeat_utc": "2026-10-24T09:44:47.323Z",
+    "route": "/api/screenshot?view=panel&window=62914560&display=%3A0",
+    "http": 200,
+    "content_type": "image/png",
+    "content_length": 1209980,
+    "source_header": "panel",
+    "decoded": {
+      "width": 1920,
+      "height": 1080,
+      "source": "panel",
+      "selected": {
+        "window": 62914560,
+        "display": ":0",
+        "name": "KDE Wayland Compositor - Press right control key to grab input",
+        "x": 0,
+        "y": 0,
+        "width": 1920,
+        "height": 1080,
+        "app": 0,
+        "focused": true
+      },
+      "stamp": "9:44:48 AM",
+      "badge": "Desktop \u00b7 KDE Wayland Compositor - Press right control key to grab input"
+    },
+    "canvas_png_bytes": 2011278,
+    "first_capture_pixel_statistics": {
+      "width": 1920,
+      "height": 1080,
+      "min": 2.3333333333333335,
+      "max": 255,
+      "hidden": false
+    },
+    "first_capture_click_event": {
+      "isTrusted": true,
+      "utc": "2026-10-24T09:44:12.738Z"
+    },
+    "actions": "Two Playwright locator.click() actions on the visible #shotBtn in the actual packaged Electron window; first click recorded isTrusted=true. No direct screenshot API invocation by harness."
+  },
+  "device_cleanup": {
+    "utc": "2026-10-24T09:45:33Z",
+    "before_stop": {
+      "exit": 0,
+      "out": "MainPID=300739\nControlGroup=/user.slice/user-1000.slice/user@1000.service/app.slice/fc-issue73-desktop-20261024.service\nActiveState=active\n",
+      "err": ""
+    },
+    "hide_dashboard": {
+      "exit": 0,
+      "out": "HideDashboard",
+      "err": ""
+    },
+    "stop_owned_unit": {
+      "exit": 0,
+      "out": "",
+      "err": ""
+    },
+    "after_stop": {
+      "exit": 0,
+      "out": "MainPID=0\nLoadState=not-found\nActiveState=inactive\n",
+      "err": ""
+    },
+    "desktop_processes": {
+      "exit": 1,
+      "out": "",
+      "err": ""
+    },
+    "nested_runtime_exists": false,
+    "session": {
+      "exit": 0,
+      "out": "Id=gamescope-session.target\nActiveState=active\nInvocationID=a2fee8ebf55c42c7b546390d14cd985c\n\nId=plasma-workspace-wayland.target\nActiveState=inactive\nInvocationID=\n\nId=gamescope-session.service\nActiveState=active\nInvocationID=e8c1085b3bbd4e79a323b3e4a9bc6355\n",
+      "err": ""
+    },
+    "steam": {
+      "exit": 0,
+      "out": "297826 /home/steamos/.local/share/Steam/steamrtarm64/steam -cef-enable-debugging -deckard -gamepadui -steamdeck -steamos3 -vrgamepadui\n",
+      "err": ""
+    },
+    "steamvr": {
+      "exit": 0,
+      "out": "297506 /opt/steamvr/bin/linuxarm64/vrserver -waitformonitor -ipccontrolfilepath /tmp/SteamVR-IPCControlFile-297420\n297620 /opt/steamvr/bin/linuxarm64/vrcompositor\n",
+      "err": ""
+    },
+    "xprops": {
+      "exit": 0,
+      "out": "GAMESCOPE_FOCUSABLE_WINDOWS(CARDINAL) = \nGAMESCOPE_FOCUSED_WINDOW(CARDINAL) = \n",
+      "err": ""
+    },
+    "battery": {
+      "capacity": "99",
+      "status": "Not charging"
+    },
+    "owned_lock_released": true
+  },
+  "host_cleanup": {
+    "electron": {
+      "pid": 1578431,
+      "exists_after": false
+    },
+    "xvfb": {
+      "pid": 1578428,
+      "exists_after": false
+    },
+    "x_socket_absent": true
+  },
+  "delayed_final_readback": "2026-10-24T09:46:39Z\nshared-lock-absent\nLoadState=not-found\nActiveState=inactive\nId=gamescope-session.target\nActiveState=active\n\nId=plasma-workspace-wayland.target\nActiveState=inactive\nInvocationID=e8c1085b3bbd4e79a323b3e4a9bc6355\n297826 /home/steamos/.local/share/Steam/steamrtarm64/steam -cef-enable-debugging -deckard -gamepadui -steamdeck -steamos3 -vrgamepadui\n297506 /opt/steamvr/bin/linuxarm64/vrserver -waitformonitor -ipccontrolfilepath /tmp/SteamVR-IPCControlFile-297420\n297620 /opt/steamvr/bin/linuxarm64/vrcompositor\nnested-runtime-absent\n100\nFull\nGAMESCOPE_FOCUSABLE_WINDOWS(CARDINAL) = \nGAMESCOPE_FOCUSED_WINDOW(CARDINAL) = \n",
+  "validation": {
+    "focused_panel_suite": "42 tests passed in 14.805s (test_touch.py), including production-page Node behavior tests",
+    "website": "2 tests passed (node --test site/test/*.test.mjs)",
+    "node_panels": "Passed independently (node tests/page/desk_panels.mjs)",
+    "metadata_and_links": "JSON parsed; result/cleanup assertions and relative evidence/streaming/testing links passed",
+    "diff": "git diff --check passed"
+  },
+  "limits": [
+    "SteamVR continued reporting not_visible after ShowDashboard, despite mapped X window and confirmed focus. No worn-headset visual assessment; does not establish the reporter's visible-overlay condition.",
+    "SteamOS 0.5.6 only; reporter used 0.4.5 with unknown Frame Control version and no reproduction steps.",
+    "Nested desktop launched with SteamOS steamos-nested-desktop from a bounded transient user unit using Steam display/session variables; not launched through a wearer's Steam UI.",
+    "Extracted unchanged AppImage on a virtual X display with Chromium sandbox and GPU disabled; no FUSE, physical monitor or hardware-rendering test.",
+    "No Live video, Control input or full Desktop Mode test.",
+    "Nested-desktop journal included gamescope WSI/Vulkan-hook warnings. No warning was dismissed; captured compositor pixels were nonblank.",
+    "Initial CDP response.body() yielded zero bytes despite successful image decode. Repeat verified Content-Length, fresh decoded image, panel selection and PNG export from canvas; the initial raw-body size is not treated as capture failure or proof.",
+    "No private desktop pixels, issue screenshot or raw desktop journal committed."
+  ]
+}

docs/evidence/desktop-capture-packaged-2026-10-24.md

@@ -0,0 +1,100 @@
+# Packaged Desktop Capture, 2026-10-24
+
+Base: `de931bc`. Package: Linux x86_64 **v0.4.17**. Device: real Frame,
+SteamOS **0.5.6**, BUILD_ID **20261015.6141207**. Host: lxso2.
+[Sanitized state and response evidence](desktop-capture-packaged-2026-10-24.json).
+
+## Result and issue boundary
+
+The packaged app discovered the nested KDE compositor and both automated
+Desktop **Capture** button clicks succeeded. The repeat returned HTTP 200,
+`Content-Type: image/png`, `X-Capture-Source: panel`, and Content-Length
+1,209,980. The app decoded a fresh, nonblank 1920×1080 image and displayed
+the Desktop panel badge. No further product failure was reproduced or fixed.
+
+This does **not** establish the full visible-desktop condition in
+[#73](https://github.com/saphid/frame-control/issues/73). `xwininfo` reported
+the desktop window `IsViewable`, and gamescope confirmed focus after
+`vrcmd --showdashboard valve.steam.desktopgame.0`. However, SteamVR still
+reported that overlay `not_visible`. There was no worn-headset visual check.
+The observation proves capture of a mapped nested compositor, not its visible
+presentation to a wearer. Do not close #73 from this evidence.
+
+The issue screenshot shows a desktop panel in the headset view while Desktop
+Capture logs “no app panel is open in the headset.” The reporter used SteamOS
+0.4.5, gave no Frame Control version or reproduction steps, and has not replied
+to the maintainer's 0.4.3 update request. The duplicate page function was already
+fixed; [PR #152](https://github.com/saphid/frame-control/pull/152) subsequently
+improved unknown-state diagnostics. Its [earlier investigation](panel-discovery-2026-10-24.md)
+was blocked from starting a desktop by another task's lock. This run adds a
+current-package capture observation, without reproducing the older failure.
+
+## Procedure
+
+1. Read-only preflight found Game Mode active, full Plasma inactive, Steam and
+   SteamVR running, battery 99%, no nested desktop/runtime and no test lock.
+2. Compared the retained AppImage's SHA-256 with the live v0.4.17 release asset
+   digest: `b1b8eb82bf73a227b2cd36e8f0ef3a2ebdf7967c5853efb08a9634f38227015d`.
+   Extracted an independent copy; `cmp` confirmed its `frame_touch.py` matches
+   the base checkout. No payload was edited.
+3. Started the package's own AppRun, bundled server and Python on Xvfb `:139`
+   with private config/cache/data/profile, telemetry and update checks disabled,
+   and `--no-sandbox --disable-gpu`. Used the existing authorized `ssh frame`
+   identity. T3 preview opened the package server page but does not attach to
+   the existing Electron window. The literal Electron button test used the
+   same Playwright-over-loopback-CDP workflow as the earlier packaged tests.
+4. Acquired `/tmp/frame-test.lock` with atomic `mkdir` and wrote an owner marker.
+   Rechecked no nested runtime or Plasma was present. Started SteamOS's
+   `/usr/bin/steamos-nested-desktop` in the owned transient user unit
+   `fc-issue73-desktop-20261024.service`, using Steam's display/session variables.
+   `RuntimeMaxSec=180s`, `TimeoutStopSec=15s` and `KillMode=control-group` bounded
+   the session. This launches a desktop panel inside Game Mode; no full Desktop
+   Mode switch was sent.
+5. In the actual packaged Electron window, navigated Tools → Capture & Live →
+   Desktop and clicked Capture with `locator.click()`. The first click event
+   recorded `isTrusted=true`. The page selected the KDE compositor on `:0`;
+   the production screenshot path used window `62914560`. Requested the desktop
+   dashboard, read back focus/visibility, and clicked Capture again. Recorded
+   response metadata, fresh decoded image dimensions and canvas pixel range.
+   No direct screenshot API call was substituted for these button clicks.
+6. Ran the packaged `frame_touch.py panels` read-only over SSH to retain its
+   exact discovery result: one focused KDE compositor panel, app ID 0, 1920×1080,
+   display `:0`, with no diagnostic `why` field.
+
+## Cleanup and limits
+
+The owned desktop session ran **09:43:48–09:45:33 UTC** (105 seconds). Hid the
+dashboard to restore its initial hidden state, stopped only the owned unit,
+and verified it was unloaded/inactive with MainPID 0. No Plasma/KWin desktop
+process or nested runtime remained; gamescope's focusable/focused lists were
+empty again. Released only this task's lock, after checking its owner marker.
+
+Delayed readback at **09:46:39 UTC** confirmed the lock absent, Game Mode active,
+full Plasma inactive and the original Steam, vrserver and vrcompositor PIDs
+still running. The Game Mode service invocation was unchanged. Battery was
+99% at cleanup and 100%/Full on the delayed check. Closed both owned preview
+tabs, Electron and Xvfb; their processes and X socket were gone. No test server
+remained. No reboot, installation, security/global setting change or full
+Desktop Mode transition was performed.
+
+The nested desktop journal included gamescope WSI/Vulkan-hook warnings. No
+warning was dismissed. Capture produced nonblank compositor pixels, but this
+run does not assess their usability to a wearer. Private image files stayed
+outside the repository; only state and response metadata are published.
+
+The initial CDP `response.body()` read yielded zero bytes despite successful
+decoding in the page. The repeat verified the PNG Content-Length, fresh image
+dimensions/source/selection and a 2,011,278-byte PNG exported from the canvas.
+The initial raw-body measurement is a harness limitation, not evidence of a
+product capture failure. No Live video, Control input, physical monitor, FUSE
+mounting or hardware rendering was tested. Older SteamOS and other packages
+remain outside this observation.
+
+## Offline verification
+
+`python3 -m unittest discover -s tests -p test_touch.py -v`: **42 tests passed**,
+including the production page's Node panel behavior tests, duplicate-function
+guard, absent versus empty panel diagnostics, alternate displays, capture/input
+target validation and discovery deadlines. JSON parsing and `git diff --check`
+were also checked. No new regression test was added because this is an
+evidence-only change with no reproduced product defect.

docs/evidence/panel-layout-2026-10-24.md

@@ -0,0 +1,168 @@
+# Saved panel layouts: feasibility recheck, 2026-10-24
+
+Issue: [#31](https://github.com/saphid/frame-control/issues/31). Base: main
+`5b47cd3`. This investigation covers spatial save/restore for existing
+Steam/gamescope panels without another overlay application.
+
+## Decision and user behavior
+
+Keep saved layouts unavailable. The current Frame exposes some geometry,
+including a standing-space coordinate transform, but this investigation did
+not establish a complete dock-state snapshot or a controlled restore path for
+these panels. The existing companion/headset switcher still lists panels and
+requests focus; users arrange them with SteamVR's dashboard controls. No layout
+file, new control, overlay application or background service is added.
+
+This is a limit of the investigated route, not proof that every native
+implementation is impossible. In particular, failure of
+`GetOverlayTransformAbsolute` does **not** mean all pose readback is denied.
+
+## Device and read-only results
+
+SteamOS **0.5.6**, BUILD_ID **20261015.6141207**; `vrcmd --version`:
+**2.18.2**. `gamescope-session.service` was active and
+`plasma-workspace.target` inactive: Game Mode. gamescope used the OpenVR backend
+and `--virtual-connector-strategy PerAppId`. Battery was 99%, Not charging,
+before the probe and 100%, Full, afterwards.
+
+The [exact probe](panel-layout-2026-10-24/probe.py) loads only
+`FnTable:IVROverlay_028` from the shipped
+`/opt/steamvr/bin/linuxarm64/libopenvr_api.so`. It uses application type 3
+(`VRApplication_Background`, avoiding runtime startup) and shuts down its own
+OpenVR connection in `finally`. Initialization and interface acquisition both
+returned 0. It calls getters only, with no image capture or input injection.
+
+[Raw result](panel-layout-2026-10-24/readback.json):
+
+| Getter | `valve.steam.desktopgame.0` | `valve.steam.gamepadui.main` |
+|---|---|---|
+| FindOverlay | 0, Success | 0, Success |
+| Rendering process | `gamescope-wl` | `gamescope-wl` |
+| Width | 0; 2.6700000763 m | 0; 2.6670000553 m |
+| Curvature | 0; 0 | 0; 0 |
+| Transform type | 0; 5, DashboardTab | 0; 5, DashboardTab |
+| Absolute transform | 18, WrongTransformType | 18, WrongTransformType |
+| Tracked-device-relative transform | 18, WrongTransformType | 18, WrongTransformType |
+| Coordinate transform, center, standing origin | 0; identity matrix | 0; scaled/translated matrix |
+| Coordinate transform, center, seated origin | 23, RequestFailed | 23, RequestFailed |
+| Coordinate transform, center, raw origin | 23, RequestFailed | 23, RequestFailed |
+
+The dashboard and both panels were reported hidden; neither panel was active.
+The standing-space matrix is the transform for the overlay point `(0.5, 0.5)`;
+it does not identify World/Dashboard/Theater/controller docking or recreate a
+dashboard frame. The Steam panel's basis has scale about 0.369. Treat neither
+that scaled matrix nor the hidden Gamescope panel's identity as a validated
+physical placement to feed to an absolute-transform setter. Visible placement,
+matrix freshness and correspondence to dashboard size were not checked by a
+wearer.
+
+## API and dashboard boundary
+
+The ABI and result names were checked against Valve's
+[OpenVR v2.12.14 C header](https://github.com/ValveSoftware/openvr/blob/v2.12.14/headers/openvr_capi.h)
+and [C++ interface comments](https://github.com/ValveSoftware/openvr/blob/v2.12.14/headers/openvr.h).
+That header declares `IVROverlay_028`; its SHA-256 is
+`d58a2b149e434b2b8ee25cb4253ca6157feed8092f621e78ecfed6846d35d3e4`.
+The absolute getter is explicitly limited to absolute transforms. The
+coordinate getter returns the 3D transform for a 2D overlay point. Public
+`IVROverlay_028` has no getter/setter pair for dashboard dock location or frame
+scene-graph state. The probe fails closed if that exact interface is absent.
+
+Read-only inspection of the shipped dashboard
+`/opt/steamvr/resources/webinterface/dashboard/chunk~8012d0c89.js`
+(SHA-256 `937ec62c67a481f030a416099ceb98b0fe2a702aea5a0705601c6c40d4969f6d`)
+found:
+
+- `dockLocation` reads an internal `_getDockLocation(frameID)` store;
+  `SetDockLocation` updates that store or sends a VRLink request.
+- `m_mapLastRelativeTransformForDockLocation` keeps per-location transforms.
+  World initialization requests a dashboard scene-graph transform through
+  `requestSGTransform`, then updates the component's `xfTransform`.
+- The `vrcmd_dock_overlay` handler accepts `dashboard`, `lefthand`, `righthand`,
+  `theater` and `world`. It selects the frame associated with the supplied key,
+  **falls back to the active frame if no match exists**, sets dock location and
+  may switch frame. This is not an exact pose restore or a readback response.
+
+Those are observations of shipped internal code, not proof that Frame Control
+can safely access its state through a supported external API. No dashboard
+JavaScript was injected, private store edited or VRLink command sent. The
+active-frame fallback is an additional reason not to experiment with docking
+commands on a stale key.
+
+The [2026-09-28 probe](../panels.md#saved-spatial-layouts-blocked-on-the-current-panel-route)
+on SteamOS 0.4.1 / SteamVR 2.18.1 recorded an absolute setter returning
+12 (`PermissionDenied`) on a temporary, test-owned gamescope panel. That setter
+result is **historical**, not a new test on 2.18.2. The newer read-only results
+above neither overturn nor reverify it.
+
+## Commands, safety and cleanup
+
+Read-only inspection used `ssh frame` with `BatchMode=yes` and
+`ConnectTimeout=10`, `cat /etc/os-release`, battery sysfs reads,
+`systemctl --user is-active gamescope-session.service plasma-workspace.target`,
+process inspection, and `vrcmd --version`, `--help`, `--overlays`. An initial
+`--listoverlays` attempt returned `Unknown command`; `--overlays` is the actual
+enumeration command. Dashboard sources were read/copied to local `/tmp` for
+inspection. No files were installed on the Frame.
+
+Run the retained probe from the repository root, following
+[the shared-device rules](../testing.md#headset-smoke-test). Stop if the lock is
+occupied or battery is at/below 20%; never remove another task's lock:
+
+```sh
+ssh -o BatchMode=yes -o ConnectTimeout=10 frame \
+  'set -eu; mkdir /tmp/frame-test.lock || exit 3; trap "rmdir /tmp/frame-test.lock" EXIT; timeout 25 python3 -' \
+  < docs/evidence/panel-layout-2026-10-24/probe.py
+```
+
+This command acquired the lock, completed with exit 0 and released it. A
+subsequent check confirmed the lock absent, Game Mode active, and Steam,
+`vrserver` and `vrcompositor` running. The probe's only headset filesystem
+change was creating/removing that shared lock. Its Python source ran from
+stdin. There were no test panels, installs, profiles or services to remove.
+
+No mutation test was essential: without verified dock/relative-frame readback,
+there was no exact original layout and bounded rollback to justify changing a
+panel. Existing user panels were never focused, shown, hidden, resized, moved
+or docked. No global settings, security, passwords, runtime processes or modes
+were changed; no reboot or reset occurred.
+
+## Validation and remaining gaps
+
+Existing `tests/test_panels.py` covers main-panel enumeration, hidden panels,
+focus revalidation, unavailable-runtime errors and HTTP authentication/Host/
+Origin guards. `tests/test_page_scripts.py` checks the production page's shared
+JavaScript scope. These offline checks do not prove spatial placement. The
+retained probe is evidence tooling, not a new product API; no fake layout
+backend or layout tests claiming device support were added.
+
+Validation passed:
+
+```sh
+python3 -m unittest discover -s tests -p test_panels.py -v       # 8 passed
+python3 -m unittest discover -s tests -p test_page_scripts.py -v # 5 passed
+python3 -m py_compile docs/evidence/panel-layout-2026-10-24/probe.py
+python3 -m json.tool docs/evidence/panel-layout-2026-10-24/readback.json
+git diff --check
+```
+
+The initial panel-suite attempt hit sandbox socket restrictions in four HTTP
+tests; rerunning with loopback sockets permitted passed all eight. No real
+headset connection is used by those tests. The full suite and fake Frame were
+not run for this evidence-only change.
+
+Before shipping layouts, a native route still needs proof of dock state and
+relative-frame readback, authorized restore on an owned test panel with exact
+rollback, and correspondence between saved size/pose and visible placement.
+It also needs stable source identity and a fresh capture-permission/ticket
+flow when reopening viewers. Reconnect, panel recreation, reboot recovery,
+Steam-launched gameplay, controller docking and worn-headset input were not
+tested here. The existing Frame Control-owned media renderer is not proof that
+Steam/gamescope panels can be restored. No third-party overlay app was used.
+
+## Announcement
+
+We rechecked saved panel layouts on SteamOS 0.5.6. SteamVR exposes some panel
+geometry, but we have not verified safe restoration of Steam's panel positions
+and docking. Saved layouts remain unavailable; use SteamVR's dashboard to
+arrange panels. The panel switcher continues to list and show open panels.

docs/evidence/panel-layout-2026-10-24/probe.py

@@ -0,0 +1,89 @@
+"""Read-only issue #31 probe; pipe to `ssh frame 'timeout 25 python3 -'`.
+
+Acquire /tmp/frame-test.lock first per docs/testing.md. No overlay is created,
+focused, docked or changed. Background init (3) does not start SteamVR.
+ABI: ValveSoftware/openvr v2.12.14 headers/openvr_capi.h, IVROverlay_028.
+"""
+import ctypes as C
+import json
+from pathlib import Path
+
+H = C.c_uint64
+Matrix = C.c_float * 12
+
+
+class Vector2(C.Structure):
+    _fields_ = [('v', C.c_float * 2)]
+
+
+def probe():
+    vr = C.CDLL('/opt/steamvr/bin/linuxarm64/libopenvr_api.so')
+    vr.VR_InitInternal2.argtypes = [C.POINTER(C.c_int), C.c_int, C.c_char_p]
+    vr.VR_InitInternal2.restype = C.c_uint32
+    vr.VR_GetGenericInterface.argtypes = [C.c_char_p, C.POINTER(C.c_int)]
+    vr.VR_GetGenericInterface.restype = C.c_void_p
+    vr.VR_ShutdownInternal.argtypes = []
+    vr.VR_ShutdownInternal.restype = None
+    err = C.c_int()
+    vr.VR_InitInternal2(C.byref(err), 3, None)
+    report = {'init_error': err.value, 'interface': 'IVROverlay_028', 'panels': []}
+    if err.value:
+        return report
+    try:
+        ptr = vr.VR_GetGenericInterface(b'FnTable:IVROverlay_028', C.byref(err))
+        report['interface_error'] = err.value
+        if err.value or not ptr:
+            return report
+        table = C.cast(ptr, C.POINTER(C.c_void_p))
+
+        def function(slot, result, *args):
+            return C.CFUNCTYPE(result, *args)(table[slot])
+
+        def read(slot, handle, output_type):
+            output = output_type()
+            rc = function(slot, C.c_int, H, C.POINTER(output_type))(handle, C.byref(output))
+            return {'rc': rc, 'value': output.value if rc == 0 else None}
+
+        report['dashboard_visible'] = function(68, C.c_bool)()
+        for key in ('valve.steam.desktopgame.0', 'valve.steam.gamepadui.main'):
+            row = {'key': key}
+            report['panels'].append(row)
+            handle = H()
+            row['find_rc'] = function(0, C.c_int, C.c_char_p, C.POINTER(H))(
+                key.encode(), C.byref(handle))
+            if row['find_rc']:
+                continue
+            pid = function(10, C.c_uint32, H)(handle)
+            row['rendering_pid'] = pid
+            try:
+                row['rendering_comm'] = Path('/proc/%d/comm' % pid).read_text().strip()
+            except OSError:
+                row['rendering_comm'] = None
+            row['visible'] = function(45, C.c_bool, H)(handle)
+            row['active_dashboard'] = function(69, C.c_bool, H)(handle)
+            row['width_m'] = read(23, handle, C.c_float)
+            row['curvature'] = read(25, handle, C.c_float)
+            row['transform_type'] = read(32, handle, C.c_int)
+            for name, slot, scalar in (('absolute', 34, C.c_int),
+                                       ('tracked_device_relative', 36, C.c_uint32)):
+                origin = scalar()
+                matrix = Matrix()
+                rc = function(slot, C.c_int, H, C.POINTER(scalar), C.POINTER(Matrix))(
+                    handle, C.byref(origin), C.byref(matrix))
+                row[name] = {'rc': rc, 'origin_or_device': origin.value if rc == 0 else None,
+                             'matrix': list(matrix) if rc == 0 else None}
+            row['coordinate_transforms'] = []
+            for origin in (0, 1, 2):  # seated, standing, raw/uncalibrated
+                matrix = Matrix()
+                rc = function(46, C.c_int, H, C.c_int, Vector2, C.POINTER(Matrix))(
+                    handle, origin, Vector2((.5, .5)), C.byref(matrix))
+                row['coordinate_transforms'].append({
+                    'tracking_origin': origin, 'coordinates': [.5, .5], 'rc': rc,
+                    'matrix': list(matrix) if rc == 0 else None})
+        return report
+    finally:
+        vr.VR_ShutdownInternal()
+
+
+if __name__ == '__main__':
+    print(json.dumps(probe(), indent=2, allow_nan=False))

docs/evidence/panel-layout-2026-10-24/readback.json

@@ -0,0 +1,152 @@
+{
+  "init_error": 0,
+  "interface": "IVROverlay_028",
+  "panels": [
+    {
+      "key": "valve.steam.desktopgame.0",
+      "find_rc": 0,
+      "rendering_pid": 297037,
+      "rendering_comm": "gamescope-wl",
+      "visible": false,
+      "active_dashboard": false,
+      "width_m": {
+        "rc": 0,
+        "value": 2.6700000762939453
+      },
+      "curvature": {
+        "rc": 0,
+        "value": 0.0
+      },
+      "transform_type": {
+        "rc": 0,
+        "value": 5
+      },
+      "absolute": {
+        "rc": 18,
+        "origin_or_device": null,
+        "matrix": null
+      },
+      "tracked_device_relative": {
+        "rc": 18,
+        "origin_or_device": null,
+        "matrix": null
+      },
+      "coordinate_transforms": [
+        {
+          "tracking_origin": 0,
+          "coordinates": [
+            0.5,
+            0.5
+          ],
+          "rc": 23,
+          "matrix": null
+        },
+        {
+          "tracking_origin": 1,
+          "coordinates": [
+            0.5,
+            0.5
+          ],
+          "rc": 0,
+          "matrix": [
+            1.0,
+            0.0,
+            0.0,
+            0.0,
+            0.0,
+            1.0,
+            0.0,
+            0.0,
+            0.0,
+            0.0,
+            1.0,
+            0.0
+          ]
+        },
+        {
+          "tracking_origin": 2,
+          "coordinates": [
+            0.5,
+            0.5
+          ],
+          "rc": 23,
+          "matrix": null
+        }
+      ]
+    },
+    {
+      "key": "valve.steam.gamepadui.main",
+      "find_rc": 0,
+      "rendering_pid": 297037,
+      "rendering_comm": "gamescope-wl",
+      "visible": false,
+      "active_dashboard": false,
+      "width_m": {
+        "rc": 0,
+        "value": 2.6670000553131104
+      },
+      "curvature": {
+        "rc": 0,
+        "value": 0.0
+      },
+      "transform_type": {
+        "rc": 0,
+        "value": 5
+      },
+      "absolute": {
+        "rc": 18,
+        "origin_or_device": null,
+        "matrix": null
+      },
+      "tracked_device_relative": {
+        "rc": 18,
+        "origin_or_device": null,
+        "matrix": null
+      },
+      "coordinate_transforms": [
+        {
+          "tracking_origin": 0,
+          "coordinates": [
+            0.5,
+            0.5
+          ],
+          "rc": 23,
+          "matrix": null
+        },
+        {
+          "tracking_origin": 1,
+          "coordinates": [
+            0.5,
+            0.5
+          ],
+          "rc": 0,
+          "matrix": [
+            0.3689989447593689,
+            0.0,
+            0.0008894503116607666,
+            -0.5048462152481079,
+            0.0,
+            0.36899998784065247,
+            0.0,
+            1.2510287761688232,
+            -0.0008894503116607666,
+            0.0,
+            0.3689989447593689,
+            -1.1726053953170776
+          ]
+        },
+        {
+          "tracking_origin": 2,
+          "coordinates": [
+            0.5,
+            0.5
+          ],
+          "rc": 23,
+          "matrix": null
+        }
+      ]
+    }
+  ],
+  "interface_error": 0,
+  "dashboard_visible": false
+}

docs/panels.md

@@ -190,7 +190,24 @@ HTTP focus is not evidence of worn-headset laser input. Follow the
 
 ## Saved spatial layouts: blocked on the current panel route
 
-**Verified 2026-09-28**, same build, using a temporary xterm panel with
+**Rechecked 2026-10-24**, SteamOS 0.5.6, BUILD_ID `20261015.6141207`,
+SteamVR 2.18.2: a read-only probe of the existing Gamescope and Steam main
+panels still reports type 5 (`DashboardTab`), and both the absolute and
+tracked-device-relative getters return 18 (`WrongTransformType`). Width and
+curvature read successfully. **Some pose readback is available:**
+`GetTransformForOverlayCoordinates` at the panel center succeeds in standing
+space; seated and raw origins return 23 (`RequestFailed`). Both panels and the
+dashboard were hidden. That matrix snapshot does not identify docking, prove
+visible placement, or establish a restore operation. The shipped dashboard
+stores dock location and relative transforms internally; no supported external
+snapshot/restore pair was established. No setters or docking commands were run
+in this recheck. See the [exact probe, results, cleanup and remaining
+gaps](evidence/panel-layout-2026-10-24.md). Saved layouts remain unavailable.
+
+### Earlier mutation evidence (2026-09-28)
+
+**Verified 2026-09-28**, SteamOS 0.4.1, BUILD_ID `20260925.6191901`,
+SteamVR 2.18.1, using a temporary xterm panel with
 `STEAM_GAME=2000999031` and `FnTable:IVROverlay_028` from
 `/opt/steamvr/bin/linuxarm64/libopenvr_api.so`:
 

docs/streaming.md

@@ -295,6 +295,10 @@ How (**verified 2026-09-29**, SteamOS 0.4.1, build 20260925.6191901):
   if it persists, report the exact message and SteamOS version. The confirmed
   empty-list advice is retained when the property is present but empty.
   [2026-10-24 investigation and verification limits](evidence/panel-discovery-2026-10-24.md).
+  A later [packaged v0.4.17 test on the real Frame](evidence/desktop-capture-packaged-2026-10-24.md)
+  captured a mapped, focused nested KDE compositor on SteamOS 0.5.6. SteamVR
+  still reported its overlay hidden, so that test does not establish the
+  wearer's visible-desktop condition in #73 or justify closing it.
 - Tested from the iPhone app (Simulator): a tap on the Desktop view focused a
   text box in the panel and the text field typed into it; a trackpad move went
   exactly (+40, +25).

docs/testing.md

@@ -165,6 +165,14 @@ Record the build, actual interaction results, cleanup and any unworn-headset
 limits alongside screenshots or logs. These are caller responsibilities; the
 smoke script below does not acquire this shared lock itself.
 
+[Packaged Desktop Capture evidence, 2026-10-24](evidence/desktop-capture-packaged-2026-10-24.md)
+records v0.4.17 GUI button captures of a real mapped nested desktop on SteamOS
+0.5.6, a bounded owned user unit, and cleanup back to the original Game Mode
+state. Check X window mapping/focus and SteamVR overlay visibility separately:
+successful capture of a mapped window does not prove the desktop is visible
+to a wearer. That run's overlay stayed `not_visible`; #73 remains unverified
+for its reported visible-desktop/0.4.5 condition. Only state/log metadata is public.
+
 ```sh
 scripts/frame-smoke.sh           # needs `ssh frame` to work without a password
 scripts/frame-smoke.sh --pair    # also pairs a throwaway key: approve it in the headset

ui/index.html

@@ -1738,7 +1738,7 @@
         <button class="small" id="sessionCheck">Check</button></div>
       <div class="sub" id="sessionState">Check which mode the headset is in.</div>
       <div class="row" style="margin-top:12px"><button class="small" id="sessionGame" disabled>Return to Game Mode</button></div>
-      <div class="hint">Uses the same switch as Valve's developer tools (<code>steamos-session-select gamescope</code>).
+      <div class="hint">Uses Valve's supported Game Mode switch for this SteamOS build.
         It closes the desktop and anything open in it. If the headset can't be reached, hold Power for 10 seconds to
         restart it; <a href="https://github.com/saphid/frame-control/blob/main/docs/backup-and-recovery.md#stuck-in-desktop-mode" target="_blank">more ways back</a>.</div>
     </section>