diff --git a/slab/menuband-win/menuband.c b/slab/menuband-win/menuband.c
index 689ecb096f..9a304ee677 100644
--- a/slab/menuband-win/menuband.c
+++ b/slab/menuband-win/menuband.c
@@ -72,7 +72,7 @@ static CRITICAL_SECTION g_lock;
 static uint32_t g_seedCounter = 0x9E3779B9u;
 static double g_sampleRate = 48000.0;
 static const double g_masterGain = 0.5;
-static volatile int g_program = 0;        // GM program for new notes (Acoustic Grand)
+static volatile int g_program = 78;       // GM program for new notes: 79 Whistle (zero-based 78), as on the Mac
 static volatile LONG g_audioRunning = 0;
 
 static double midi_freq(int midi) { return 440.0 * pow(2.0, (midi - 69) / 12.0); }
@@ -525,6 +525,7 @@ static HHOOK g_hook = NULL;
 static HWND g_strip = NULL;
 #define WM_TYPEKEY (WM_APP + 2)
 #define WM_TYPEESC (WM_APP + 3)
+#define WM_OCTAVE (WM_APP + 4)
 
 static void build_keymap(void) {
     for (int i = 0; i < 256; i++) g_semitoneByVk[i] = -128;
@@ -543,6 +544,10 @@ static LRESULT CALLBACK ll_keyboard(int code, WPARAM wp, LPARAM lp) {
         int down = (wp == WM_KEYDOWN || wp == WM_SYSKEYDOWN);
         if (!(k->flags & LLKHF_INJECTED) && k->vkCode < 256) {
             if (k->vkCode == VK_ESCAPE) { if (down) PostMessageW(g_strip, WM_TYPEESC, 0, 0); return 1; }
+            if (k->vkCode == VK_OEM_COMMA || k->vkCode == VK_OEM_PERIOD) {
+                if (down) PostMessageW(g_strip, WM_OCTAVE, k->vkCode == VK_OEM_PERIOD ? 1 : (WPARAM)-1, 0);
+                return 1;
+            }
             if (g_semitoneByVk[k->vkCode] != -128 && !(GetAsyncKeyState(VK_CONTROL) & 0x8000) && !(GetAsyncKeyState(VK_LWIN) & 0x8000)) {
                 PostMessageW(g_strip, WM_TYPEKEY, k->vkCode, down);
                 return 1;
@@ -614,15 +619,30 @@ static void track(HWND hwnd, int force) {
 #define IDM_TYPING 101
 #define IDM_AUTOSTART 102
 #define IDM_PROGRAM_BASE 200
-#define IDM_MIDI_BASE 300
+#define IDM_MIDI_BASE 400
 #define IDT_TRACK 1
 
-static const struct { const wchar_t *name; int program; } PROGRAMS[] = {
-    { L"Acoustic Grand Piano", 0 }, { L"Electric Piano", 4 }, { L"Harpsichord", 6 },
-    { L"Vibraphone", 11 }, { L"Drawbar Organ", 16 }, { L"Nylon Guitar", 24 },
-    { L"Electric Bass", 33 }, { L"Strings", 48 }, { L"Choir", 52 }, { L"Flute", 73 },
-    { L"Square Lead", 80 }, { L"Warm Pad", 89 },
+// All 128 General MIDI programs, grouped in the 16 GM families for the menu.
+static const wchar_t *GM_NAMES[128] = {
+    L"Acoustic Grand Piano", L"Bright Acoustic Piano", L"Electric Grand Piano", L"Honky-tonk Piano", L"Electric Piano 1", L"Electric Piano 2", L"Harpsichord", L"Clavinet",
+    L"Celesta", L"Glockenspiel", L"Music Box", L"Vibraphone", L"Marimba", L"Xylophone", L"Tubular Bells", L"Dulcimer",
+    L"Drawbar Organ", L"Percussive Organ", L"Rock Organ", L"Church Organ", L"Reed Organ", L"Accordion", L"Harmonica", L"Tango Accordion",
+    L"Nylon Guitar", L"Steel Guitar", L"Jazz Guitar", L"Clean Guitar", L"Muted Guitar", L"Overdriven Guitar", L"Distortion Guitar", L"Guitar Harmonics",
+    L"Acoustic Bass", L"Fingered Bass", L"Picked Bass", L"Fretless Bass", L"Slap Bass 1", L"Slap Bass 2", L"Synth Bass 1", L"Synth Bass 2",
+    L"Violin", L"Viola", L"Cello", L"Contrabass", L"Tremolo Strings", L"Pizzicato Strings", L"Orchestral Harp", L"Timpani",
+    L"String Ensemble 1", L"String Ensemble 2", L"Synth Strings 1", L"Synth Strings 2", L"Choir Aahs", L"Voice Oohs", L"Synth Voice", L"Orchestra Hit",
+    L"Trumpet", L"Trombone", L"Tuba", L"Muted Trumpet", L"French Horn", L"Brass Section", L"Synth Brass 1", L"Synth Brass 2",
+    L"Soprano Sax", L"Alto Sax", L"Tenor Sax", L"Baritone Sax", L"Oboe", L"English Horn", L"Bassoon", L"Clarinet",
+    L"Piccolo", L"Flute", L"Recorder", L"Pan Flute", L"Blown Bottle", L"Shakuhachi", L"Whistle", L"Ocarina",
+    L"Square Lead", L"Sawtooth Lead", L"Calliope Lead", L"Chiff Lead", L"Charang Lead", L"Voice Lead", L"Fifths Lead", L"Bass + Lead",
+    L"New Age Pad", L"Warm Pad", L"Polysynth Pad", L"Choir Pad", L"Bowed Pad", L"Metallic Pad", L"Halo Pad", L"Sweep Pad",
+    L"Rain", L"Soundtrack", L"Crystal", L"Atmosphere", L"Brightness", L"Goblins", L"Echoes", L"Sci-Fi",
+    L"Sitar", L"Banjo", L"Shamisen", L"Koto", L"Kalimba", L"Bagpipe", L"Fiddle", L"Shanai",
+    L"Tinkle Bell", L"Agogo", L"Steel Drums", L"Woodblock", L"Taiko Drum", L"Melodic Tom", L"Synth Drum", L"Reverse Cymbal",
+    L"Guitar Fret Noise", L"Breath Noise", L"Seashore", L"Bird Tweet", L"Telephone Ring", L"Helicopter", L"Applause", L"Gunshot",
 };
+static const wchar_t *GM_FAMILIES[16] = { L"Piano", L"Chromatic Percussion", L"Organ", L"Guitar", L"Bass", L"Strings", L"Ensemble", L"Brass", L"Reed", L"Pipe", L"Synth Lead", L"Synth Pad", L"Synth Effects", L"Ethnic", L"Percussive", L"Sound Effects" };
+
 
 static NOTIFYICONDATAW g_nid;
 
@@ -646,8 +666,15 @@ static void show_menu(HWND hwnd) {
     HMENU menu = CreatePopupMenu();
     AppendMenuW(menu, MF_STRING | (g_typing ? MF_CHECKED : 0), IDM_TYPING, L"Type to play  (Esc leaves)");
     AppendMenuW(menu, MF_SEPARATOR, 0, NULL);
-    for (int i = 0; i < (int)(sizeof PROGRAMS / sizeof PROGRAMS[0]); i++)
-        AppendMenuW(menu, MF_STRING | (PROGRAMS[i].program == g_program ? MF_CHECKED : 0), IDM_PROGRAM_BASE + i, PROGRAMS[i].name);
+    for (int f = 0; f < 16; f++) {
+        HMENU fam = CreatePopupMenu();
+        for (int i = f * 8; i < f * 8 + 8; i++) {
+            wchar_t label[64]; swprintf(label, 64, L"%d  %s", i + 1, GM_NAMES[i]);
+            AppendMenuW(fam, MF_STRING | (i == g_program ? MF_CHECKED : 0), IDM_PROGRAM_BASE + i, label);
+        }
+        wchar_t famLabel[64]; swprintf(famLabel, 64, L"%s%s", GM_FAMILIES[f], (g_program / 8 == f) ? L"  \x2713" : L"");
+        AppendMenuW(menu, MF_POPUP, (UINT_PTR)fam, famLabel);
+    }
     AppendMenuW(menu, MF_SEPARATOR, 0, NULL);
     HMENU midi = CreatePopupMenu();
     AppendMenuW(midi, MF_STRING | (g_midiDevice < 0 ? MF_CHECKED : 0), IDM_MIDI_BASE, L"Built-in synth");
@@ -676,6 +703,14 @@ static void mouse_up(HWND hwnd) {
     if (g_mouseMidi >= 0) { lit_off(hwnd, g_mouseMidi); g_mouseMidi = -1; }
 }
 
+static void shift_octave(HWND hwnd, int dir) {
+    int next = g_firstMidi + 12 * dir;
+    if (next < 36 || next > 84) return;
+    mouse_up(hwnd);
+    release_typed(hwnd);
+    g_firstMidi = next; build_keys(); push_frame(hwnd);
+}
+
 static LRESULT CALLBACK wndproc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {
     switch (msg) {
     case WM_CREATE:
@@ -716,16 +751,12 @@ static LRESULT CALLBACK wndproc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {
     case WM_RBUTTONUP:
         show_menu(hwnd);
         return 0;
-    case WM_MOUSEWHEEL: {
-        int delta = GET_WHEEL_DELTA_WPARAM(wp);
-        int next = g_firstMidi + (delta > 0 ? 12 : -12);
-        if (next >= 36 && next <= 84) {
-            mouse_up(hwnd);
-            release_typed(hwnd);
-            g_firstMidi = next; build_keys(); push_frame(hwnd);
-        }
+    case WM_MOUSEWHEEL:
+        shift_octave(hwnd, GET_WHEEL_DELTA_WPARAM(wp) > 0 ? 1 : -1);
+        return 0;
+    case WM_OCTAVE:
+        shift_octave(hwnd, (int)(intptr_t)wp);
         return 0;
-    }
     case WM_TYPEKEY: {
         int vk = (int)wp, down = (int)lp;
         if (vk < 0 || vk > 255) return 0;
@@ -745,9 +776,7 @@ static LRESULT CALLBACK wndproc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {
         if (id == IDM_QUIT) { DestroyWindow(hwnd); return 0; }
         if (id == IDM_TYPING) { typing_set(hwnd, !g_typing); return 0; }
         if (id == IDM_AUTOSTART) { autostart_set(!autostart_enabled()); return 0; }
-        if (id >= IDM_PROGRAM_BASE && id < IDM_PROGRAM_BASE + (int)(sizeof PROGRAMS / sizeof PROGRAMS[0])) {
-            g_program = PROGRAMS[id - IDM_PROGRAM_BASE].program; midi_program();
-        }
+        if (id >= IDM_PROGRAM_BASE && id < IDM_PROGRAM_BASE + 128) { g_program = id - IDM_PROGRAM_BASE; midi_program(); }
         if (id >= IDM_MIDI_BASE && id < IDM_MIDI_BASE + 40) midi_select(id - IDM_MIDI_BASE - 1);
         return 0;
     }
diff --git a/slab/windows/README.md b/slab/windows/README.md
new file mode 100644
index 0000000000..b5597c9767
--- /dev/null
+++ b/slab/windows/README.md
@@ -0,0 +1,22 @@
+# slab on Windows
+
+`slab-agent.ps1` is the `frame` agent for a Windows 11 machine. It speaks
+the same file protocol as `FrameCapture.swift` inside the Mac menubar app,
+so `frame <machine>` from a Mac works unchanged: the client ships its
+request over `ssh host bash -s`, Git bash answers on Windows, and the agent
+(resident in the signed-in desktop session) produces the envelope.
+
+- Observe: GDI screen capture (foreground window by default, `screen` for
+  all of it, `crop=x,y,w,h`), Windows.Media.Ocr text with click centres, a
+  UI Automation walk of the foreground window as the `ax` tree, visible
+  windows, cursor, DPI. JPEG thumb ≤ 1568 px.
+- Act: `native-click=` / `native-drag=` through SendInput.
+- Coordinates are physical pixels (`coordinateSpace: windows-physical-pixels`).
+
+Install on the box: copy to `~\src\slab\slab-agent.ps1`, put Git's `bin`
+on the machine PATH (for `bash -s`), start it inside the desktop session
+(a scheduled task running as the user, or the HKCU Run key `SlabAgent`).
+Register the machine in `~/.config/slab/puppet.json` with an `sshHost`.
+Windows PowerShell 5.1 only; it is the one with WinRT.
+
+Timings on a MiniBook X: ~0.7 s warm (OCR dominates), ~4 s cold.
diff --git a/slab/windows/slab-agent.ps1 b/slab/windows/slab-agent.ps1
new file mode 100644
index 0000000000..a8a67be52f
--- /dev/null
+++ b/slab/windows/slab-agent.ps1
@@ -0,0 +1,297 @@
+# slab-agent.ps1 — the slab `frame` agent for a Windows 11 box.
+#
+# Speaks the same file protocol as FrameCapture.swift inside the Mac
+# menubar app, so `frame <machine>` on a Mac works unchanged against a
+# Windows machine (the client ships its request over `ssh host bash -s`,
+# which Git bash answers here):
+#
+#   ~/.local/share/slab/state/frame.req       mode line, written by the client
+#   ~/.local/share/slab/state/frame.out.json  envelope
+#   ~/.local/share/slab/state/frame.out.jpg   thumbnail (≤ 1568 px wide)
+#   ~/.local/share/slab/state/frame.done      touched when both are written
+#
+# Mode tokens honoured: window (default) | screen, noocr, fast, novisual,
+# crop=x,y,w,h, cursor=x,y, session=…, native-click=<b64 json>,
+# native-drag=<b64 json>, native-guard=<b64 json>. Unknown tokens are ignored.
+#
+# Observes with GDI (CopyFromScreen), reads text with Windows.Media.Ocr, walks
+# the foreground window with UI Automation, and sends real input with
+# SendInput. Must run INSIDE the signed-in desktop session (start it through
+# the ac-desk task or the Run key), never from an ssh session: those have no
+# desktop to capture. Windows PowerShell 5.1 only — it is the one with WinRT.
+
+$ErrorActionPreference = 'Continue'
+Add-Type -AssemblyName System.Drawing, System.Windows.Forms, System.Runtime.WindowsRuntime, UIAutomationClient, UIAutomationTypes
+
+Add-Type @"
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+public class SlabNative {
+  [DllImport("user32.dll")] public static extern bool SetProcessDPIAware();
+  [DllImport("user32.dll")] public static extern IntPtr GetForegroundWindow();
+  [DllImport("user32.dll")] public static extern bool GetWindowRect(IntPtr h, out RECT r);
+  [DllImport("user32.dll")] public static extern uint GetWindowThreadProcessId(IntPtr h, out uint pid);
+  [DllImport("user32.dll", CharSet = CharSet.Unicode)] public static extern int GetWindowTextW(IntPtr h, StringBuilder s, int n);
+  [DllImport("user32.dll")] public static extern bool GetCursorPos(out POINT p);
+  [DllImport("user32.dll")] public static extern bool SetCursorPos(int x, int y);
+  [DllImport("user32.dll")] public static extern uint SendInput(uint n, INPUT[] inputs, int size);
+  [DllImport("user32.dll")] public static extern bool EnumWindows(EnumProc cb, IntPtr l);
+  [DllImport("user32.dll")] public static extern bool IsWindowVisible(IntPtr h);
+  [DllImport("dwmapi.dll")] public static extern int DwmGetWindowAttribute(IntPtr h, int attr, out RECT r, int size);
+  public delegate bool EnumProc(IntPtr h, IntPtr l);
+  [StructLayout(LayoutKind.Sequential)] public struct RECT { public int Left, Top, Right, Bottom; }
+  [StructLayout(LayoutKind.Sequential)] public struct POINT { public int X, Y; }
+  [StructLayout(LayoutKind.Sequential)] public struct MOUSEINPUT { public int dx, dy; public uint mouseData, dwFlags, time; public IntPtr dwExtraInfo; }
+  [StructLayout(LayoutKind.Sequential)] public struct KEYBDINPUT { public ushort wVk, wScan; public uint dwFlags, time; public IntPtr dwExtraInfo; }
+  [StructLayout(LayoutKind.Explicit)] public struct INPUTUNION { [FieldOffset(0)] public MOUSEINPUT mi; [FieldOffset(0)] public KEYBDINPUT ki; }
+  [StructLayout(LayoutKind.Sequential)] public struct INPUT { public uint type; public INPUTUNION u; }
+  public static void Mouse(uint flags, int dx, int dy, uint data) {
+    INPUT[] i = new INPUT[1]; i[0].type = 0; i[0].u.mi.dwFlags = flags; i[0].u.mi.dx = dx; i[0].u.mi.dy = dy; i[0].u.mi.mouseData = data;
+    SendInput(1, i, Marshal.SizeOf(typeof(INPUT)));
+  }
+  public static void Key(ushort vk, bool up) {
+    INPUT[] i = new INPUT[1]; i[0].type = 1; i[0].u.ki.wVk = vk; i[0].u.ki.dwFlags = up ? 2u : 0u;
+    SendInput(1, i, Marshal.SizeOf(typeof(INPUT)));
+  }
+}
+"@
+[SlabNative]::SetProcessDPIAware() | Out-Null
+
+# ── WinRT OCR plumbing (Windows PowerShell 5.1) ──────────────────────────
+[void][Windows.Media.Ocr.OcrEngine, Windows.Foundation, ContentType = WindowsRuntime]
+[void][Windows.Graphics.Imaging.BitmapDecoder, Windows.Foundation, ContentType = WindowsRuntime]
+[void][Windows.Storage.Streams.InMemoryRandomAccessStream, Windows.Foundation, ContentType = WindowsRuntime]
+[void][Windows.Globalization.Language, Windows.Foundation, ContentType = WindowsRuntime]
+$asTaskGeneric = ([System.WindowsRuntimeSystemExtensions].GetMethods() | Where-Object {
+  $_.Name -eq 'AsTask' -and $_.GetParameters().Count -eq 1 -and $_.GetParameters()[0].ParameterType.Name -eq 'IAsyncOperation`1' })[0]
+function Await($op, $type) {
+  $t = $asTaskGeneric.MakeGenericMethod($type).Invoke($null, @($op)); $t.Wait(-1) | Out-Null; $t.Result
+}
+$script:ocr = [Windows.Media.Ocr.OcrEngine]::TryCreateFromUserProfileLanguages()
+if (-not $script:ocr) { $script:ocr = [Windows.Media.Ocr.OcrEngine]::TryCreateFromLanguage([Windows.Globalization.Language]::new('en-US')) }
+
+function Ocr-Bitmap([System.Drawing.Bitmap]$bmp, [int]$ox, [int]$oy) {
+  if (-not $script:ocr) { return @() }
+  $ms = New-Object System.IO.MemoryStream
+  $bmp.Save($ms, [System.Drawing.Imaging.ImageFormat]::Bmp); $ms.Position = 0
+  $ras = [System.IO.WindowsRuntimeStreamExtensions]::AsRandomAccessStream($ms)
+  $dec = Await ([Windows.Graphics.Imaging.BitmapDecoder]::CreateAsync($ras)) ([Windows.Graphics.Imaging.BitmapDecoder])
+  $sb = Await ($dec.GetSoftwareBitmapAsync()) ([Windows.Graphics.Imaging.SoftwareBitmap])
+  $res = Await ($script:ocr.RecognizeAsync($sb)) ([Windows.Media.Ocr.OcrResult])
+  $out = New-Object System.Collections.ArrayList
+  foreach ($line in $res.Lines) {
+    $x0 = 1e9; $y0 = 1e9; $x1 = -1e9; $y1 = -1e9
+    foreach ($w in $line.Words) { $r = $w.BoundingRect; if ($r.X -lt $x0) { $x0 = $r.X }; if ($r.Y -lt $y0) { $y0 = $r.Y }; if ($r.X + $r.Width -gt $x1) { $x1 = $r.X + $r.Width }; if ($r.Y + $r.Height -gt $y1) { $y1 = $r.Y + $r.Height } }
+    if ($x1 -le $x0) { continue }
+    [void]$out.Add([ordered]@{ t = $line.Text; cx = [int]($ox + ($x0 + $x1) / 2); cy = [int]($oy + ($y0 + $y1) / 2); r = @([int]($ox + $x0), [int]($oy + $y0), [int]($x1 - $x0), [int]($y1 - $y0)) })
+  }
+  $ms.Dispose()
+  ,$out.ToArray()
+}
+
+# ── UI Automation (the AX tree's cousin) ────────────────────────────────
+$roleMap = @{ 'ControlType.Button' = 'AXButton'; 'ControlType.Edit' = 'AXTextField'; 'ControlType.Text' = 'AXStaticText'; 'ControlType.CheckBox' = 'AXCheckBox';
+  'ControlType.RadioButton' = 'AXRadioButton'; 'ControlType.ComboBox' = 'AXPopUpButton'; 'ControlType.Hyperlink' = 'AXLink'; 'ControlType.MenuItem' = 'AXMenuItem';
+  'ControlType.ListItem' = 'AXRow'; 'ControlType.TabItem' = 'AXRadioButton'; 'ControlType.Slider' = 'AXSlider'; 'ControlType.Image' = 'AXImage'; 'ControlType.Window' = 'AXWindow' }
+function Walk-Uia([IntPtr]$hwnd, [int]$cap, [int]$budgetMs) {
+  $els = New-Object System.Collections.ArrayList
+  try {
+    $root = [System.Windows.Automation.AutomationElement]::FromHandle($hwnd)
+    $walker = [System.Windows.Automation.TreeWalker]::ControlViewWalker
+    $queue = New-Object System.Collections.Generic.Queue[System.Windows.Automation.AutomationElement]
+    $queue.Enqueue($root)
+    $sw = [System.Diagnostics.Stopwatch]::StartNew()
+    while ($queue.Count -gt 0 -and $els.Count -lt $cap -and $sw.ElapsedMilliseconds -lt $budgetMs) {
+      $el = $queue.Dequeue()
+      try {
+        $c = $el.Current
+        if (-not $c.IsOffscreen -and $c.BoundingRectangle.Width -gt 0) {
+          $ct = $c.ControlType.ProgrammaticName
+          $role = if ($roleMap.ContainsKey($ct)) { $roleMap[$ct] } else { 'UIA' + ($ct -replace 'ControlType\.', '') }
+          $acts = New-Object System.Collections.ArrayList
+          if ($el.GetCurrentPropertyValue([System.Windows.Automation.AutomationElement]::IsInvokePatternAvailableProperty)) { [void]$acts.Add('AXPress') }
+          if ($el.GetCurrentPropertyValue([System.Windows.Automation.AutomationElement]::IsTogglePatternAvailableProperty)) { [void]$acts.Add('AXPress') }
+          if ($el.GetCurrentPropertyValue([System.Windows.Automation.AutomationElement]::IsValuePatternAvailableProperty)) { [void]$acts.Add('AXSetValue') }
+          if ($c.Name -or $acts.Count -gt 0) {
+            $b = $c.BoundingRectangle
+            [void]$els.Add([ordered]@{ role = $role; title = [string]$c.Name; cx = [int]($b.X + $b.Width / 2); cy = [int]($b.Y + $b.Height / 2);
+              r = @([int]$b.X, [int]$b.Y, [int]$b.Width, [int]$b.Height); actions = @($acts | Select-Object -Unique) })
+          }
+        }
+      } catch {}
+      try { $child = $walker.GetFirstChild($el); while ($child -ne $null) { $queue.Enqueue($child); $child = $walker.GetNextSibling($child) } } catch {}
+    }
+  } catch {}
+  ,$els.ToArray()
+}
+
+# ── helpers ─────────────────────────────────────────────────────────────
+function Window-Title([IntPtr]$h) { $sb = New-Object System.Text.StringBuilder 512; [void][SlabNative]::GetWindowTextW($h, $sb, 512); $sb.ToString() }
+function Window-Bounds([IntPtr]$h) {
+  $r = New-Object SlabNative+RECT
+  if ([SlabNative]::DwmGetWindowAttribute($h, 9, [ref]$r, 16) -ne 0) { [void][SlabNative]::GetWindowRect($h, [ref]$r) }
+  $r
+}
+function Visible-Windows([int]$cap) {
+  $list = New-Object System.Collections.ArrayList
+  $cb = [SlabNative+EnumProc]{ param($h, $l)
+    if ($list.Count -ge $cap) { return $false }
+    if ([SlabNative]::IsWindowVisible($h)) { $t = Window-Title $h; if ($t) { $b = Window-Bounds $h; $wpid = 0; [void][SlabNative]::GetWindowThreadProcessId($h, [ref]$wpid)
+      $app = try { (Get-Process -Id $wpid -ErrorAction Stop).ProcessName } catch { '?' }
+      [void]$list.Add([ordered]@{ app = $app; title = $t; pid = [int]$wpid; x = $b.Left; y = $b.Top; w = $b.Right - $b.Left; h = $b.Bottom - $b.Top }) } }
+    $true }
+  [void][SlabNative]::EnumWindows($cb, [IntPtr]::Zero)
+  ,$list.ToArray()
+}
+function Save-Jpeg([System.Drawing.Bitmap]$bmp, [string]$path, [int]$maxW) {
+  $img = $bmp
+  if ($bmp.Width -gt $maxW) { $h = [int]($bmp.Height * $maxW / $bmp.Width); $img = New-Object System.Drawing.Bitmap $bmp, $maxW, $h }
+  $codec = [System.Drawing.Imaging.ImageCodecInfo]::GetImageEncoders() | Where-Object { $_.MimeType -eq 'image/jpeg' }
+  $ep = New-Object System.Drawing.Imaging.EncoderParameters 1
+  $ep.Param[0] = New-Object System.Drawing.Imaging.EncoderParameter ([System.Drawing.Imaging.Encoder]::Quality), 72L
+  $img.Save($path, $codec, $ep)
+  if ($img -ne $bmp) { $img.Dispose() }
+}
+function Decode-B64Json($s) { try { [System.Text.Encoding]::UTF8.GetString([Convert]::FromBase64String($s)) | ConvertFrom-Json } catch { $null } }
+
+# ── native input ────────────────────────────────────────────────────────
+function Move-To([int]$x, [int]$y) {
+  $sw = [System.Windows.Forms.Screen]::PrimaryScreen.Bounds
+  $nx = [int]($x * 65535 / ($sw.Width - 1)); $ny = [int]($y * 65535 / ($sw.Height - 1))
+  [SlabNative]::Mouse(0x8001, $nx, $ny, 0)   # MOVE | ABSOLUTE
+}
+function Click-At($req) {
+  $x = [int]$req.x; $y = [int]$req.y
+  $button = if ($req.button) { [string]$req.button } else { 'left' }
+  $count = if ($req.count) { [int]$req.count } else { 1 }
+  $down = 0x0002; $up = 0x0004
+  if ($button -eq 'right') { $down = 0x0008; $up = 0x0010 }
+  Move-To $x $y; Start-Sleep -Milliseconds 20
+  if ($req.drag) {
+    [SlabNative]::Mouse($down, 0, 0, 0)
+    $steps = [Math]::Max(2, [int]([double]($(if ($req.drag.durationMs) { $req.drag.durationMs } else { 160 })) / 8))
+    for ($i = 1; $i -le $steps; $i++) { Move-To ([int]($x + ($req.drag.x - $x) * $i / $steps)) ([int]($y + ($req.drag.y - $y) * $i / $steps)); Start-Sleep -Milliseconds 8 }
+    [SlabNative]::Mouse($up, 0, 0, 0)
+    return [ordered]@{ sent = $true; kind = 'drag'; from = @($x, $y); to = @([int]$req.drag.x, [int]$req.drag.y) }
+  }
+  for ($i = 0; $i -lt $count; $i++) {
+    [SlabNative]::Mouse($down, 0, 0, 0)
+    if ($req.holdMs) { Start-Sleep -Milliseconds ([int]$req.holdMs) } else { Start-Sleep -Milliseconds 12 }
+    [SlabNative]::Mouse($up, 0, 0, 0)
+    if ($i -lt $count - 1) { Start-Sleep -Milliseconds 60 }
+  }
+  [ordered]@{ sent = $true; kind = 'click'; x = $x; y = $y; button = $button; count = $count }
+}
+
+# ── one observation ─────────────────────────────────────────────────────
+$state = "$HOME\.local\share\slab\state"
+New-Item -ItemType Directory -Force $state | Out-Null
+$utf8 = New-Object System.Text.UTF8Encoding $false
+
+function Trace($m) { try { Add-Content -Path "$state\agent.trace" -Value ("{0:HH:mm:ss.fff} {1}" -f (Get-Date), $m) } catch {} }
+function Produce([string]$mode) {
+  Trace "produce: $mode"
+  $t0 = [System.Diagnostics.Stopwatch]::StartNew()
+  $tm = [ordered]@{}
+  $tokens = $mode -split ' ' | Where-Object { $_ }
+  $flags = @{}; foreach ($tk in $tokens) { $flags[$tk] = $true }
+  $session = ($tokens | Where-Object { $_ -like 'session=*' } | Select-Object -First 1); if ($session) { $session = $session.Substring(8) } else { $session = 'legacy' }
+  $fr = [ordered]@{ capture = 'ok'; capture_scope = 'window'; coordinateSpace = 'windows-physical-pixels' }
+
+  # Native input first, then observe what it did.
+  $nativeToken = $tokens | Where-Object { $_ -like 'native-click=*' -or $_ -like 'native-drag=*' -or $_ -like 'native-guard=*' } | Select-Object -First 1
+  if ($nativeToken) {
+    $kind, $b64 = $nativeToken -split '=', 2
+    $req = Decode-B64Json $b64
+    if (-not $req) { $fr.nativeInput = @{ error = 'Invalid native request; no action sent' } }
+    elseif ($kind -eq 'native-guard') { $fr.nativeInput = @{ guard = 'ok' } }
+    else { $ti = [System.Diagnostics.Stopwatch]::StartNew(); $fr.nativeInput = Click-At $req; $fr.nativeInput.ms = $ti.ElapsedMilliseconds; Start-Sleep -Milliseconds 120 }
+    $fr.nativeCapabilities = @('guarded-click-v1', 'guarded-drag-v1', 'click-hold-v1')
+  }
+
+  Trace "geometry"
+  # Geometry.
+  $screen = [System.Windows.Forms.Screen]::PrimaryScreen.Bounds
+  $scale = [Math]::Round(([System.Drawing.Graphics]::FromHwnd([IntPtr]::Zero)).DpiX / 96, 2)
+  $fg = [SlabNative]::GetForegroundWindow()
+  $fgPid = 0; [void][SlabNative]::GetWindowThreadProcessId($fg, [ref]$fgPid)
+  $fgApp = try { (Get-Process -Id $fgPid -ErrorAction Stop).ProcessName } catch { '?' }
+  $fgTitle = Window-Title $fg
+  $wb = Window-Bounds $fg
+  $region = $screen
+  if ($flags['screen'] -or $fg -eq [IntPtr]::Zero -or ($wb.Right - $wb.Left) -le 0) { $fr.capture_scope = 'screen' }
+  else { $region = New-Object System.Drawing.Rectangle ([Math]::Max(0, $wb.Left)), ([Math]::Max(0, $wb.Top)), ([Math]::Min($screen.Width, $wb.Right) - [Math]::Max(0, $wb.Left)), ([Math]::Min($screen.Height, $wb.Bottom) - [Math]::Max(0, $wb.Top)) }
+  $cropTok = $tokens | Where-Object { $_ -like 'crop=*' } | Select-Object -First 1
+  if ($cropTok) { $c = $cropTok.Substring(5) -split ','; if ($c.Count -eq 4) { $region = New-Object System.Drawing.Rectangle ([int]$c[0]), ([int]$c[1]), ([int]$c[2]), ([int]$c[3]); $fr.capture_scope = 'crop' } }
+  if ($region.Width -le 0 -or $region.Height -le 0) { $region = $screen; $fr.capture_scope = 'screen' }
+  if ($fr.capture_scope -ne 'screen') { $fr.crop = [ordered]@{ x = $region.X; y = $region.Y; w = $region.Width; h = $region.Height } }
+
+  Trace "pixels"
+  # Pixels.
+  $t = [System.Diagnostics.Stopwatch]::StartNew()
+  $bmp = New-Object System.Drawing.Bitmap $region.Width, $region.Height
+  $g = [System.Drawing.Graphics]::FromImage($bmp)
+  $g.CopyFromScreen($region.Location, [System.Drawing.Point]::Empty, $region.Size); $g.Dispose()
+  $tm.capture = $t.ElapsedMilliseconds
+
+  Trace "meta"
+  # Meta.
+  $t.Restart()
+  $cur = New-Object SlabNative+POINT; [void][SlabNative]::GetCursorPos([ref]$cur)
+  $fr.meta = [ordered]@{
+    host = $env:COMPUTERNAME; os = 'windows'
+    screen = [ordered]@{ w = $screen.Width; h = $screen.Height; scale = $scale }
+    cursor = [ordered]@{ x = $cur.X; y = $cur.Y }
+    frontmost = [ordered]@{ app = $fgApp; pid = [int]$fgPid; title = $fgTitle; bundle = $fgApp }
+    windows = [object[]](Visible-Windows 24)
+  }
+  $tm.meta = $t.ElapsedMilliseconds
+
+  Trace "ocr"
+  # OCR.
+  $t.Restart()
+  if ($flags['noocr']) { $fr.ocr = @() } else { $fr.ocr = [object[]](Ocr-Bitmap $bmp $region.X $region.Y) }
+  $tm.ocr = $t.ElapsedMilliseconds
+
+  Trace "uia"
+  # UIA.
+  $t.Restart()
+  $cap = if ($flags['fast']) { 80 } else { 300 }
+  $els = if ($fg -ne [IntPtr]::Zero) { [object[]](Walk-Uia $fg $cap 600) } else { @() }
+  $fr.ax = [ordered]@{ trusted = $true; app = $fgApp; scope = $(if ($fr.capture_scope -eq 'screen') { 'application' } else { 'window' }); elements = $els }
+  $tm.ax = $t.ElapsedMilliseconds
+
+  $fr.visual = @()
+  $fr.observation = [ordered]@{ id = [guid]::NewGuid().ToString(); session = $session; windowId = [int64]$fg; kind = 'frame'; coordinateSpace = 'windows-physical-pixels' }
+
+  Trace "thumb"
+  # Thumb + envelope.
+  $t.Restart()
+  $jpg = "$state\frame.out.jpg"; $json = "$state\frame.out.json"
+  Save-Jpeg $bmp $jpg 1568
+  $bmp.Dispose()
+  $fr.thumb_bytes = (Get-Item $jpg).Length
+  $tm.thumb = $t.ElapsedMilliseconds
+  $tm.wall = $t0.ElapsedMilliseconds
+  $fr.timings_ms = $tm
+  [IO.File]::WriteAllText($json, ($fr | ConvertTo-Json -Depth 8 -Compress), $utf8)
+  Trace "done $($tm.wall)ms"
+}
+
+# ── request loop ────────────────────────────────────────────────────────
+$req = "$state\frame.req"; $done = "$state\frame.done"
+"slab-agent up in session $([System.Diagnostics.Process]::GetCurrentProcess().SessionId) · ocr=$([bool]$script:ocr) · $state"
+while ($true) {
+  if (Test-Path $req) {
+    $mode = ''
+    try { $mode = [IO.File]::ReadAllText($req) } catch {}
+    Remove-Item $req -Force -ErrorAction SilentlyContinue
+    try { Produce $mode } catch {
+      [IO.File]::WriteAllText("$state\frame.out.json", (@{ capture = 'error'; reason = "$($_.Exception.Message)" } | ConvertTo-Json -Compress), $utf8)
+      Remove-Item "$state\frame.out.jpg" -Force -ErrorAction SilentlyContinue
+    }
+    [IO.File]::WriteAllText($done, 'ok', $utf8)
+  }
+  Start-Sleep -Milliseconds 15
+}