Clarify Game Mode switch help for current SteamOS

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

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+- 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/backup-and-recovery.md

@@ -25,8 +25,28 @@ tested in another full Plasma session under a three-minute rollback timer.
 `ui/frame_backup.py session` reported Desktop Mode despite gamescope, and
 `ui/frame_backup.py game-mode` invoked the same guarded Return function used by
 the button. Game Mode became active and a second call made no switch. Battery
-remained at 99%; the timer and lock were removed. The literal desktop button
-was not clicked in this test, and older SteamOS builds remain fixture-tested.
+remained at 99%; the timer and lock were removed. That test used the production
+CLI rather than clicking the desktop button.
+
+Later on 2026-10-24, the published **v0.4.17 Linux x86_64 AppImage** passed the
+literal packaged-button check on the same Frame/build. With the shared lock and
+a verified three-minute rollback timer, the headset entered full Plasma Desktop
+Mode. In the packaged Electron window, **Tools → Backup & recovery → Check**
+reported Desktop Mode despite gamescope. A trusted automated pointer click on
+the visible **Return to Game Mode** button, accepting its confirmation, returned
+`switched: true` and `steamosctl switch-to-game-mode`. The systemd targets then
+confirmed Game Mode. A second confirmed button click returned `switched: false`;
+the Game Mode service invocation and SteamVR PID stayed unchanged. **Check**
+then reported Game Mode and disabled Return. The test app/server and virtual
+display were stopped; the timer and shared lock were removed. Steam and SteamVR remained running
+at 99% battery. [Commands, responses, cleanup and limits](evidence/return-game-mode-packaged-2026-10-24.json),
+[before](evidence/return-game-mode-packaged-2026-10-24-before.png) and
+[after](evidence/return-game-mode-packaged-2026-10-24-after.png).
+
+This used the unchanged extracted AppImage payload with its bundled Python on
+Xvfb (`--no-sandbox --disable-gpu`), following the packaged Export test in #156.
+FUSE mounting, desktop integration, hardware rendering and the view inside a
+worn headset were not checked. Older SteamOS builds remain fixture-tested.
 
 ## Back up
 

docs/evidence/clip-packaged-export-2026-10-24.json

@@ -0,0 +1,94 @@
+{
+  "date_utc": "2026-10-24T09:08:35.523Z",
+  "result": "PASS: packaged Electron visible Export click saved the retained real Steam clip beyond 60 seconds",
+  "frame_control_tag": "v0.4.17",
+  "documentation_base_commit": "4e456480aefbe541e334dbd247328537f535bd94",
+  "host": "lxso2",
+  "steamos_version": "0.5.6",
+  "steamos_build": "20261015.6141207",
+  "package": {
+    "asset": "Frame-Control-linux-x86_64.AppImage",
+    "url": "https://github.com/saphid/frame-control/releases/download/v0.4.17/Frame-Control-linux-x86_64.AppImage",
+    "sha256": "b1b8eb82bf73a227b2cd36e8f0ef3a2ebdf7967c5853efb08a9634f38227015d",
+    "launch": "Verified release asset; --appimage-extract, then unmodified squashfs-root/AppRun. Electron used the bundled server and Python, not checkout source.",
+    "display": "Xvfb :137, 1440x1000x24; Electron window 1400x950 including native chrome",
+    "flags": [
+      "--no-sandbox",
+      "--disable-gpu",
+      "--remote-debugging-port=49371",
+      "--remote-debugging-address=127.0.0.1",
+      "--user-data-dir=/tmp/frame-packaged-export-20261024/electron-profile"
+    ],
+    "isolation": "Throwaway XDG_CONFIG_HOME, FRAME_CONTROL_DATA_DIR and Electron profile; telemetry and update checks disabled; existing SSH identity and normal home Videos destination used."
+  },
+  "ui": {
+    "navigation": "Dismissed optional email prompt with No thanks; clicked Tools, then Capture & Live; scrolled Steam clips into view.",
+    "row": "Steam recording \u00b7 Clip; Oct 24, 8:53 AM \u00b7 1:40 \u00b7 2 MB",
+    "action": "Playwright connected to this Electron instance over local CDP; locator.click() clicked its visible button named exactly Export. The test did not directly invoke an export function or API POST.",
+    "button": "button.small[data-clip-export=\"0\"]",
+    "click_is_trusted": true,
+    "button_bounds_css_pixels": {
+      "x": 1300.390625,
+      "y": 701.15625,
+      "width": 61.609375,
+      "height": 28
+    },
+    "post_clips_export_http": 200,
+    "job": "0ab20b1788adce63",
+    "job_poll_http": 200,
+    "saved_message": "Saved clip_15658413054201167872_20261024_085343.mp4 to ~/Videos/SteamFrame",
+    "final_row": "ON PC; Export again",
+    "screenshots": [
+      "clip-packaged-export-2026-10-24-before.png",
+      "clip-packaged-export-2026-10-24-after.png"
+    ],
+    "screenshot_scope": "Cropped to Steam clip rows and saved notification; unrelated screenshot thumbnails and host connection identity excluded."
+  },
+  "source": {
+    "clip_id": "10230640/clips/clip_15658413054201167872_20261024_085343",
+    "duration_seconds": 100.801,
+    "duration_provenance": "Retained real Steam clip from clip-long-2026-10-24.json; current packaged UI displays 1:40."
+  },
+  "output": {
+    "path": "~/Videos/SteamFrame/clip_15658413054201167872_20261024_085343.mp4",
+    "bytes": 1377849,
+    "sha256": "82ef31f65e6933d122bc326d664beb2eb2e3ba6969f26c0032552e80fbe8d823",
+    "matches_prior_production_export_size_and_sha256": true,
+    "duration_seconds_ffprobe": 100.833335,
+    "duration_difference_from_steam_seconds": 0.032335,
+    "video": "H.264, 1920x1080, 6049 decoded frames",
+    "audio": "AAC, 48000 Hz, stereo, 4724 decoded audio frames",
+    "validation": [
+      "ffprobe -v error -count_frames -show_entries format=duration,size:stream=codec_name,codec_type,width,height,sample_rate,channels,nb_read_frames -of json <output>: exit 0",
+      "sha256sum <output>: exact match to prior production export",
+      "ffmpeg -v error -xerror -i <output> -f null -: exit 0, no errors"
+    ]
+  },
+  "cleanup": {
+    "shared_lock": "Acquired with ssh frame mkdir /tmp/frame-test.lock after read-only battery/build/lock checks; released with rmdir after app shutdown; absence read back.",
+    "battery_percent_before": 99,
+    "battery_percent_after": 99,
+    "battery_status": "Not charging; charger Full",
+    "packaged_app_and_server_exited": true,
+    "test_xvfb_stopped": true,
+    "frame_export_cache_directories_remaining": 0,
+    "ffmpeg_processes_after": 0,
+    "game_mode_and_steamvr_running_after": true,
+    "steam_source_clip_retained": true,
+    "user_recordings_deleted": false,
+    "headset_install_or_settings_changes": false,
+    "local_export_retained": true
+  },
+  "limits": [
+    "The unchanged AppImage payload ran after extraction on a virtual X desktop, with Chromium sandbox and GPU disabled. FUSE mounting, desktop integration and hardware rendering were not tested.",
+    "The click was automated trusted pointer input in a visible Electron window on Xvfb, not a human click on a physical monitor. T3 collaborative preview opened successfully but drives separate browser tabs; Electron-native automation was used for this window.",
+    "No new game or Steam recording was started. Visible gameplay quality, audible content and perceptual audio/video sync were not assessed.",
+    "Clips longer than this retained 100-second clip, trims and automatic copying remain unverified.",
+    "No release, tag or application code was changed."
+  ],
+  "validation_local": {
+    "clip_regression_suite": "python3 -m unittest discover -s tests -p test_clips.py -v: 34 tests passed in 20.173s, including real ffmpeg long-recording export",
+    "json": "python3 -m json.tool: passed",
+    "diff": "git diff --check: passed"
+  }
+}

docs/evidence/linux-pc-host-lxso2-2026-10-24.md

@@ -0,0 +1,114 @@
+# Linux PC host feasibility on lxso2, 2026-10-24
+
+**Blocked on this host's current desktop environment. No feature enabled and
+no feature PR opened.** Investigation for [issue #23](https://github.com/saphid/frame-control/issues/23),
+starting at `4e45648` (main after #154). This concerns flat desktop panels,
+not Linux PC VR streaming.
+
+## Decision
+
+The smallest useful candidate is one explicitly selected **whole screen**,
+captured through the ScreenCast portal's restricted PipeWire connection,
+encoded locally with GStreamer/x264, and sent to the existing viewer through
+the shared SSH controller. Input, individual windows and virtual displays
+would remain unsupported until separately verified. This candidate was **not
+implemented**: lxso2 currently cannot exercise the real capture permission path.
+
+Development packages could unblock compilation, but would not create a desktop,
+portal backend or consented screen. Synthetic encoding, an Xvfb screen grab or
+using the Frame as its own host would not verify Linux PC desktop capture.
+No host packages or services were changed.
+
+## Evidence
+
+Host: `lxso2`, Linux x86-64, kernel `6.8.0-139-generic`.
+
+- `DISPLAY`, `WAYLAND_DISPLAY` and `XDG_SESSION_TYPE` were unset. The user bus
+  was reachable at `/run/user/1000/bus`.
+- `/run/user/1000/pipewire-0` and `/run/user/1000/wayland-0` did not exist.
+  No processes matched Xorg, Xwayland, Xvfb, GNOME Shell, KWin Wayland, Weston,
+  PipeWire, WirePlumber or xdg-desktop-portal at the process check.
+- D-Bus `ListNames` returned D-Bus, systemd and anonymous connections, with no
+  `org.freedesktop.portal.Desktop`. `ListActivatableNames` also had no desktop
+  portal. These calls queried D-Bus itself without activating capture services.
+- `dpkg-query` found no `xdg-desktop-portal*` or `pipewire*` packages.
+  `libgstreamer1.0-0:amd64` was installed at `1.24.2-1ubuntu0.1`, but
+  `gstreamer1.0-tools` was uninstalled. `gst-launch-1.0` and `gst-inspect-1.0`
+  were absent from PATH. Xvfb was installed, but supplies no portal by itself.
+- `pkg-config --modversion` failed for `gstreamer-1.0`,
+  `gstreamer-app-1.0`, `gstreamer-video-1.0` and `libpipewire-0.3`.
+  `gio-unix-2.0` reported `2.80.0`.
+- `desktop/bundle/pc-host.so` did not exist.
+  `python3 desktop/build.py --with-x264 --out /tmp/frame-linux-pc-feasibility`
+  exited **1** before compilation: required GStreamer pkg-config modules were
+  missing. No native build or encoder runtime success is claimed.
+
+Reproduce the non-activating portal checks in the intended desktop user's
+session, using that session's actual runtime directory and bus:
+
+```sh
+gdbus call --session --dest org.freedesktop.DBus \
+  --object-path /org/freedesktop/DBus --method org.freedesktop.DBus.ListNames
+gdbus call --session --dest org.freedesktop.DBus \
+  --object-path /org/freedesktop/DBus --method org.freedesktop.DBus.ListActivatableNames
+pkg-config --modversion gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0 gio-unix-2.0
+```
+
+## Existing implementation reviewed
+
+- `ui/frame_pcview.py` selects PCView only on Windows and rejects Linux even
+  when enabled. Linux installers do not carry its native bundle.
+- `desktop/portal.c` creates a **RemoteDesktop** session, requests pointer and
+  keyboard devices, and selects monitors and windows (`types=3`). It is not
+  ScreenCast-only or screen-only. Its restricted fd/node and fresh-connection
+  handling are reusable.
+- `ui/frame_pc_agent.py` calls the selection a shared window or screen and
+  picks VA-API when the element is present, falling back to x264. A bounded
+  x264 slice needs explicit encoder policy and unsupported-input behavior;
+  exposing the existing Linux path alone would not meet that scope.
+- `app/main.js` starts Python with the inherited environment; it does not
+  supply a compositor, portal backend or capture permission.
+- `.github/workflows/pc-host.yml` installs native dependencies and tests
+  synthetic x264/protocol behavior with fake capture consent/input. This does
+  not establish interactive Linux desktop capture.
+- Issue #23 and its six existing comments distinguish prior synthetic
+  helper/viewer results from untested Linux desktop capture and consent.
+
+## Verification and limits
+
+`python3 -m unittest discover -s tests -p 'test_pc*.py' -v` exited **0**:
+27 tests ran successfully, with one additional native-class setup skip
+(`native PC libraries not built on this host`). Coverage includes the compiled
+C controller trace, Python adapters, grants and default-off/Windows-only gates.
+It does not prove native GStreamer capture or local-client streaming.
+
+No fake/local native stream, consent prompt, real desktop capture, Frame viewer
+run, benchmark, input or window mode was tested in this investigation. No SSH
+connection to the Frame was needed; no lock was acquired and no headset install,
+launch, stop or settings change was attempted. Issue #113 was left alone.
+No issue comments or other public messages were sent.
+
+## Concrete unblock and next slice
+
+1. Supply an interactive Linux desktop, physical or VM, with a working
+   ScreenCast portal/backend, PipeWire and accessible consent dialog. Installing
+   the portal frontend alone is insufficient. A VM can establish software
+   capture/x264 behavior while physical-host behavior remains unverified.
+2. Install the native dependencies listed in `pc-host.yml` in that environment
+   and build a local `--with-x264` bundle. Resolve x264 distribution
+   licensing/source obligations before shipping it: the current build labels
+   that option test-only and the Windows installer omits it.
+3. Implement a ScreenCast-only session with monitor-only selection, no
+   RemoteDesktop/device request, disabled input in protocol and viewer, hidden
+   window/virtual-display modes, and explicit x264 selection. Preserve the
+   default-off gate and existing Mac/Windows paths.
+4. Verify consent acceptance/refusal/cancellation, Stop/reopen, connection loss
+   and portal closure with a local client decoding actual captured content.
+   Run the shared benchmark and record results without inferring hardware or
+   physical laser behavior.
+5. Only after local capture works, acquire the shared Frame lock once and
+   follow [the headset procedure](../testing.md#headset-smoke-test) for a brief
+   viewer test. If occupied, leave the lock alone and defer device testing.
+
+These are prerequisites and proposed scope, not a ready feature. The Linux
+host request in #23 remains open.

docs/evidence/return-game-mode-packaged-2026-10-24.json

@@ -0,0 +1,226 @@
+{
+  "date_utc": "2026-10-24T09:27:25.354Z",
+  "result": "PASS: literal packaged desktop Return to Game Mode button switched the real Frame from full Plasma; a repeat visible click made no second switch",
+  "documentation_base_commit": "71288d8980040c14f777f0e417f41f7105eaaac4",
+  "host": "lxso2",
+  "steamos_version": "0.5.6",
+  "steamos_build": "20261015.6141207",
+  "prior_evidence": [
+    "https://github.com/saphid/frame-control/issues/142",
+    "https://github.com/saphid/frame-control/pull/143",
+    "https://github.com/saphid/frame-control/pull/156"
+  ],
+  "package": {
+    "tag": "v0.4.17",
+    "asset": "Frame-Control-linux-x86_64.AppImage",
+    "url": "https://github.com/saphid/frame-control/releases/download/v0.4.17/Frame-Control-linux-x86_64.AppImage",
+    "sha256": "b1b8eb82bf73a227b2cd36e8f0ef3a2ebdf7967c5853efb08a9634f38227015d",
+    "verification": "sha256sum matched the live release asset digest. Independently extracted the retained asset into a new private test directory. cmp confirmed bundled frame_backup.py and frame_backup_remote.py equal the checkout versions. No source or payload was changed.",
+    "launch": "--appimage-extract, then squashfs-root/AppRun --no-sandbox --disable-gpu --remote-debugging-port=49372 --remote-debugging-address=127.0.0.1 --user-data-dir=/tmp/frame-return-button-20261024/electron-profile --window-size=1400,950",
+    "display": "Xvfb :138 -screen 0 1440x1000x24 -nolisten tcp; Electron content screenshot 1400x923",
+    "isolation": "Private XDG_CONFIG_HOME, XDG_CACHE_HOME, FRAME_CONTROL_DATA_DIR and Electron profile; FRAME_CONTROL_TELEMETRY=0 and FRAME_CONTROL_NO_UPDATE_CHECK=1. Existing authorized ssh frame identity retained; bundled server and Python used."
+  },
+  "preflight": {
+    "read_only_first": true,
+    "initial_mode": "gamescope-session.target=active; plasma-workspace-wayland.target=inactive",
+    "initial_battery_percent": 99,
+    "initial_battery_status": "Not charging; charger Full",
+    "steam_and_steamvr_running": true,
+    "running_steam_apps": [],
+    "default_login_mode": "game",
+    "lock": "mkdir /tmp/frame-test.lock succeeded atomically; no foreign lock was removed. Initial harmless probe attempt released its own lock, then a fresh atomic acquisition covered both full-session attempts."
+  },
+  "rollback": {
+    "unit": "fc-return-button-rollback-20261024",
+    "probe": "systemd-run --user --unit=fc-return-button-probe-20261024 --on-active=2s --timer-property=AccuracySec=1s --property=Type=oneshot --property=RemainAfterExit=yes /usr/bin/true",
+    "probe_execution": "Result=success\nExecMainStartTimestamp=Sat 2026-10-24 20:27:07 AEDT\nExecMainExitTimestamp=Sat 2026-10-24 20:27:07 AEDT\nExecMainCode=1\nExecMainStatus=0\n",
+    "arm": "systemd-run --user --unit=fc-return-button-rollback-20261024 --on-active=180s --timer-property=AccuracySec=1s /bin/sh -c <guarded command>",
+    "guarded_command": "if [ \"$(systemctl --user is-active gamescope-session.target)\" != active ]; then exec /usr/bin/steamosctl switch-to-game-mode; fi",
+    "verified_before_desktop": "TimersMonotonic={ OnActiveUSec=3min ; next_elapse=1d 21h 53min 49.130174s }\nNextElapseUSecMonotonic=1d 21h 53min 49.130174s\nBindsTo=\nPartOf=\nActiveState=active\nExecStart={ path=/bin/sh ; argv[]=/bin/sh -c if [ \"$(systemctl --user is-active gamescope-session.target)\" != active ]; then exec /usr/bin/steamosctl switch-to-game-mode; fi ; ignore_errors=no ; start_time=[n/a] ; stop_time=[n/a] ; pid=0 ; code=(null) ; status=0/0 }\nBindsTo=\nPartOf=\n",
+    "user_manager_linger": "yes",
+    "desktop_entry": "ssh frame steamosctl switch-to-desktop-mode",
+    "first_click_utc": "2026-10-24T09:27:27.037Z",
+    "cancelled_before_deadline": true,
+    "fired": false,
+    "limit": "The benign transient timer was observed executing. The actual rollback timer configuration was read back, then cancelled after the UI restored Game Mode; its recovery action was not deliberately allowed to fire."
+  },
+  "ui": {
+    "navigation": "Clicked nav Tools, Backup & recovery, and Check in the actual packaged Electron window. Initial Game Mode disabled Return. After full Plasma entry, Check enabled it.",
+    "automation": "Playwright connected to the packaged Electron instance over local CDP and used locator.click() on the visible button; accepted the native JavaScript confirm dialog. No Return API/CLI or production handler was directly invoked by the test. T3 preview was inspected separately and closed; it cannot control this Electron window.",
+    "clicks": [
+      {
+        "isTrusted": true,
+        "utc": "2026-10-24T09:27:27.037Z"
+      },
+      {
+        "isTrusted": true,
+        "utc": "2026-10-24T09:27:32.942Z"
+      }
+    ],
+    "button_bounds_css_pixels": {
+      "x": 47,
+      "y": 709.59375,
+      "width": 156.203125,
+      "height": 44
+    },
+    "confirmation_dialogs": [
+      {
+        "type": "confirm",
+        "message": "Return the headset to Game Mode?\n\nThis closes the desktop and any apps open in it, then starts Steam's Game Mode.",
+        "utc": "2026-10-24T09:27:27.042Z"
+      },
+      {
+        "type": "confirm",
+        "message": "Return the headset to Game Mode?\n\nThis closes the desktop and any apps open in it, then starts Steam's Game Mode.",
+        "utc": "2026-10-24T09:27:32.943Z"
+      }
+    ],
+    "desktop_check": {
+      "http": 200,
+      "body": {
+        "mode": "desktop",
+        "gamescope": true,
+        "plasma": true,
+        "nested_desktop": false,
+        "configured": "gamescope-wayland.desktop",
+        "config_file": "/etc/sddm.conf.d/steamos.conf",
+        "selector": "steamosctl",
+        "session_targets": {
+          "gamescope-session.target": "inactive",
+          "plasma-workspace-wayland.target": "active"
+        },
+        "mode_source": "session-targets"
+      }
+    },
+    "return_responses": [
+      {
+        "http": 200,
+        "body": {
+          "message": "Asked the headset to return to Game Mode; it restarts its session in a few seconds",
+          "state": {
+            "mode": "desktop",
+            "gamescope": true,
+            "plasma": true,
+            "nested_desktop": false,
+            "configured": "gamescope-wayland.desktop",
+            "config_file": "/etc/sddm.conf.d/steamos.conf",
+            "selector": "steamosctl",
+            "session_targets": {
+              "gamescope-session.target": "inactive",
+              "plasma-workspace-wayland.target": "active"
+            },
+            "mode_source": "session-targets"
+          },
+          "switched": true,
+          "command": "steamosctl switch-to-game-mode"
+        },
+        "utc": "2026-10-24T09:27:27.316Z"
+      },
+      {
+        "http": 200,
+        "body": {
+          "message": "The headset is already in Game Mode. The desktop you see is a panel: close it from the Steam dashboard.",
+          "state": {
+            "mode": "game",
+            "gamescope": true,
+            "plasma": false,
+            "nested_desktop": false,
+            "configured": "gamescope-wayland.desktop",
+            "config_file": "/etc/sddm.conf.d/steamos.conf",
+            "selector": "steamosctl",
+            "session_targets": {
+              "gamescope-session.target": "active",
+              "plasma-workspace-wayland.target": "inactive"
+            },
+            "mode_source": "session-targets"
+          },
+          "switched": false
+        },
+        "utc": "2026-10-24T09:27:33.126Z"
+      }
+    ],
+    "final_check": {
+      "http": 200,
+      "body": {
+        "mode": "game",
+        "gamescope": true,
+        "plasma": false,
+        "nested_desktop": false,
+        "configured": "gamescope-wayland.desktop",
+        "config_file": "/etc/sddm.conf.d/steamos.conf",
+        "selector": "steamosctl",
+        "session_targets": {
+          "gamescope-session.target": "active",
+          "plasma-workspace-wayland.target": "inactive"
+        },
+        "mode_source": "session-targets"
+      }
+    },
+    "final_return_disabled": true,
+    "final_text": "Game Mode: the headset is running normally. A desktop you see is a panel; close it from the Steam dashboard.",
+    "screenshots": [
+      "return-game-mode-packaged-2026-10-24-before.png",
+      "return-game-mode-packaged-2026-10-24-after.png"
+    ],
+    "screenshot_scope": "Cropped to the session controls and repeat-action notification; host identity, connection address and backup folder excluded."
+  },
+  "systemd_verification": {
+    "command": "ssh frame systemctl --user show gamescope-session.target plasma-workspace-wayland.target -p Id -p ActiveState -p SubState; ssh frame systemctl --user show gamescope-session.service -p InvocationID",
+    "before": "Id=gamescope-session.target\nActiveState=inactive\nSubState=dead\n\nId=plasma-workspace-wayland.target\nActiveState=active\nSubState=active\nInvocationID=892b843dbe1a4d2ba91b93057bd38463\n295589 /home/steamos/.local/share/Steam/steamrtarm64/steam -silent -vrdisable -deckard\n295066 /opt/steamvr/bin/linuxarm64/vrserver -waitformonitor -ipccontrolfilepath /tmp/SteamVR-IPCControlFile-294978\n",
+    "after_first_click": "Id=gamescope-session.target\nActiveState=active\nSubState=active\n\nId=plasma-workspace-wayland.target\nActiveState=inactive\nSubState=dead\nInvocationID=e8c1085b3bbd4e79a323b3e4a9bc6355\n297506 /opt/steamvr/bin/linuxarm64/vrserver -waitformonitor -ipccontrolfilepath /tmp/SteamVR-IPCControlFile-297420\n",
+    "after_repeat_click": "Id=gamescope-session.target\nActiveState=active\nSubState=active\n\nId=plasma-workspace-wayland.target\nActiveState=inactive\nSubState=dead\nInvocationID=e8c1085b3bbd4e79a323b3e4a9bc6355\n297826 /home/steamos/.local/share/Steam/steamrtarm64/steam -cef-enable-debugging -deckard -gamepadui -steamdeck -steamos3 -vrgamepadui\n297942 /home/steamos/.local/share/Steam/steamrtarm64/steam -child-update-ui -child-update-ui-socket 8 -cef-enable-debugging -deckard -gamepadui -steamdeck -steamos3 -vrgamepadui\n297506 /opt/steamvr/bin/linuxarm64/vrserver -waitformonitor -ipccontrolfilepath /tmp/SteamVR-IPCControlFile-297420\n",
+    "repeat_did_not_restart_game_mode": true,
+    "unchanged_game_service_invocation": "e8c1085b3bbd4e79a323b3e4a9bc6355",
+    "unchanged_steamvr_pid": 297506,
+    "delayed_final_readback_utc": "2026-10-24T09:28:05Z"
+  },
+  "cleanup": {
+    "complete": true,
+    "final_readback": "2026-10-24T09:28:05Z\nId=gamescope-session.target\nActiveState=active\n\nId=plasma-workspace-wayland.target\nActiveState=inactive\nInvocationID=e8c1085b3bbd4e79a323b3e4a9bc6355\nNEXT LEFT LAST PASSED UNIT ACTIVATES\n\n0 timers listed.\nId=fc-return-button-rollback-20261024.timer\nLoadState=not-found\nActiveState=inactive\n\nId=fc-return-button-rollback-20261024.service\nLoadState=not-found\nActiveState=inactive\n\nId=fc-return-button-probe-20261024.timer\nLoadState=not-found\nActiveState=inactive\n\nId=fc-return-button-probe-20261024.service\nLoadState=not-found\nActiveState=inactive\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\n99\nCharging\ngame\n",
+    "owned_lock_release_exit": 0,
+    "owned_lock_absent": true,
+    "host_processes": {
+      "xvfb": {
+        "pid": 1562020,
+        "exists": false,
+        "cmd": null,
+        "state": null
+      },
+      "electron": {
+        "pid": 1562023,
+        "exists": false,
+        "cmd": null,
+        "state": null
+      },
+      "x_socket_absent": true
+    },
+    "remaining_test_servers": [],
+    "battery_final_percent": 99,
+    "battery_final_status": "Charging",
+    "battery_range_observed_percent": [
+      99,
+      100
+    ],
+    "game_mode_steam_steamvr_running": true,
+    "default_login_mode_after": "game",
+    "headset_installs_or_global_settings_changed": false,
+    "rebooted": false,
+    "notes": "Stopping the timer succeeded. systemctl stop also named its never-started, unloaded service and returned 5; explicit readback confirms both rollback and probe timer/service units are not-found/inactive. No further switch was sent."
+  },
+  "attempts_and_harness_limits": [
+    "Initial harmless timer probe was garbage-collected before its exit metadata could be read. No Desktop Mode switch was attempted. Repeated with RemainAfterExit=yes and verified successful execution.",
+    "First full Plasma attempt clicked the visible packaged Return button and got HTTP 200 / switched=true. The harness then treated absent pgrep matches during the expected session restart as a fatal error. Independent readback confirmed Game Mode and SteamVR had returned. Rollback remained armed until that readback, then was cancelled. This incomplete attempt was not counted as the final pass.",
+    "Final full Plasma attempt tolerated transiently absent Steam/SteamVR while polling systemd targets, passed both trusted visible clicks, and completed the final Check. Stopping the unused rollback service returned unit-not-loaded; explicit subsequent readback verified all four owned probe/rollback units not-found/inactive and zero timers. Cleanup was completed before releasing our lock."
+  ],
+  "limits": [
+    "Unchanged AppImage payload ran after extraction on a virtual X desktop with Chromium sandbox and GPU disabled. FUSE mounting, desktop integration and hardware rendering were not tested.",
+    "Automated trusted pointer clicks in a visible Electron window; no physical-monitor human click or worn-headset visual/interaction assessment.",
+    "Verified only SteamOS 0.5.6 build 20261015.6141207 and the Linux x86_64 v0.4.17 package; older selectors/builds and other desktop platforms remain covered only by their existing tests.",
+    "No release, tag, application code, passwords or security/global settings changed."
+  ],
+  "validation": {
+    "focused_suite": "python3 -m unittest discover -s tests -p test_backup.py -v: 28 tests passed in 2.479s",
+    "json": "python3 -m json.tool: passed",
+    "diff": "git diff --check: passed"
+  }
+}

docs/pc-in-headset.md

@@ -107,6 +107,12 @@ The Linux adapter from #38 (desktop portal, PipeWire, VA-API) is in the tree,
 because it shares `capture.c` and the controller, and CI still builds and tests
 it. The app never offers it and the Linux installers don't include it.
 
+The [2026-10-24 lxso2 feasibility check](evidence/linux-pc-host-lxso2-2026-10-24.md)
+found no running or activatable desktop portal, no PipeWire socket and missing
+native build dependencies. Linux support remains disabled. The evidence records
+the build failure and prerequisites for a screen-only, view-only x264 slice;
+Linux capture, input and window modes have not been verified there.
+
 ## Measuring
 
 The Mac benchmark accepts the PC host:

docs/recording.md

@@ -178,17 +178,33 @@ copied MP4 was **100.833 seconds** by `ffprobe` and decoded completely with
 `ffmpeg`; it was not cut at 60 seconds. The test restored Steam's recording
 mode, removed its reserved title and processes, and left Game Mode active at
 100% battery. See [the long-clip evidence](evidence/clip-long-2026-10-24.json).
-This did not click **Export** in the packaged desktop app or verify visible
-gameplay quality or perceptual audio/video sync.
+That code-path test did not click **Export** in the packaged desktop app or
+verify visible gameplay quality or perceptual audio/video sync.
+
+Later that day, the published v0.4.17 x86_64 Linux AppImage also passed the
+packaged desktop **Export** check against the retained 100.801-second clip.
+The asset SHA-256 was verified before launching its unchanged extracted payload
+in an isolated Electron profile on a virtual X desktop. An automated pointer
+click on the visible **Tools → Capture & Live → Steam clips → Export** button
+saved the MP4 and changed the row to **ON PC / Export again**. The saved file
+was 100.833335 seconds, decoded completely, and matched the prior production
+export by size and SHA-256. The app and test display were closed,
+the Frame export cache was empty, the source clip was retained, and the shared
+lock was released at 99% battery with Game Mode and SteamVR still running.
+See [the packaged export evidence](evidence/clip-packaged-export-2026-10-24.json)
+and its cropped before/after screenshots. This verifies the packaged Electron
+button and bundled export path; AppImage FUSE mounting, desktop integration,
+physical display/GPU rendering, gameplay quality and perceptual sync remain
+unverified. The virtual-display launch used `--no-sandbox --disable-gpu`.
 
 Remaining checks include:
 
 - Perceptual audio/video sync and audible content. Frame Control's separate
   **Record** path stamps camera and audio inputs with the wall clock because
   they otherwise count from different clocks.
-- Clips longer than the 100-second test, trims starting partway through a Steam
-  recording, and the packaged desktop app's **Export** button. Two real saved
-  clips' directory layouts were checked; the parser remains deliberately loose
+- Clips longer than the 100-second test and trims starting partway through a
+  Steam recording. Two real saved clips' directory layouts were checked; the
+  parser remains deliberately loose
   for other layouts.
 - How much x264 at 1080p30 costs the Frame while a game is running.
 - Automatic copying: that 30 seconds without a write is a safe sign Steam has

docs/streaming.md

@@ -7,6 +7,9 @@ This covers three directions, plus input:
 - **C. iPhone → Frame**: mirror the phone inside the headset.
 - **PC VR from Linux**: [feasibility and options](linux-vr-streaming.md),
   including Valve's streaming and USB support. No Linux host tested yet.
+- **Linux desktop → Frame panels**: [PC-host feasibility on lxso2](evidence/linux-pc-host-lxso2-2026-10-24.md).
+  Blocked on missing desktop portal/PipeWire and native build dependencies;
+  Linux desktop capture remains disabled and unverified.
 - **Input**: type and point in the Frame from the Mac or iPhone.
 - **Live view and Control**: watch a panel flat and tap on it to use it.
 

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>