diff --git a/tools/capture_evidence.ps1 b/tools/capture_evidence.ps1
new file mode 100644
index 0000000..97bebd5
--- /dev/null
+++ b/tools/capture_evidence.ps1
@@ -0,0 +1,143 @@
+# 2b evidence capture: byte-safe device screenshots of each acceptance state.
+# ASCII-only source. Screenshots go through tools\shot.ps1 because PS 5.1 `>`
+# writes UTF-16 and corrupts PNG bytes (see that file's header).
+# Text/state assertions use uiautomator (lessons R-6: vivo logcat is throttled).
+
+$ErrorActionPreference = "Stop"
+$repo = (Resolve-Path "$PSScriptRoot\..").Path
+$ev   = "D:\working\projects\yuankong\evidence\2b"
+$adb  = "D:\working\android\sdk\platform-tools\adb.exe"
+$phoneIp = "192.168.1.180"
+
+function Adb-Shell {
+    param([Parameter(Mandatory)][string[]]$Cmd)
+    $old = $ErrorActionPreference
+    $ErrorActionPreference = "Continue"
+    try {
+        $out = & $adb shell @Cmd 2>$null
+        return @{ out = ($out -join "`n"); code = $LASTEXITCODE }
+    }
+    finally { $ErrorActionPreference = $old }
+}
+
+function Get-Ui {
+    [void](Adb-Shell @("uiautomator", "dump", "/sdcard/ui.xml"))
+    $old = $ErrorActionPreference
+    $ErrorActionPreference = "Continue"
+    try { & $adb pull /sdcard/ui.xml "$env:TEMP\cap-ui.xml" 2>$null | Out-Null }
+    finally { $ErrorActionPreference = $old }
+    if (-not (Test-Path "$env:TEMP\cap-ui.xml")) { return "" }
+    return [System.IO.File]::ReadAllText("$env:TEMP\cap-ui.xml", [System.Text.Encoding]::UTF8)
+}
+
+function Wait-Live([int]$Seconds) {
+    $deadline = (Get-Date).AddSeconds($Seconds)
+    while ((Get-Date) -lt $deadline) {
+        Start-Sleep -Milliseconds 900
+        $x = Get-Ui
+        if ($x -match "RTT=") { return $x }
+    }
+    return ""
+}
+
+function Shot([string]$name) {
+    $out = Join-Path $ev $name
+    & powershell -NoProfile -ExecutionPolicy Bypass -File "$repo\tools\shot.ps1" -Out $out
+}
+
+New-Item -ItemType Directory -Force -Path $ev | Out-Null
+# drop the earlier broken captures (PS 5.1 '>' wrote them as UTF-16)
+Get-ChildItem $ev -Filter "*.png" | ForEach-Object {
+    $b = [System.IO.File]::ReadAllBytes($_.FullName)
+    if ($b.Length -lt 4 -or ($b[0] -ne 0x89)) { Remove-Item $_.FullName -Force }
+}
+
+Write-Host "=== ensure fresh v3 agent ==="
+$agentExe = "$repo\target\release\agent.exe"
+$ag = Get-Process agent -ErrorAction SilentlyContinue
+if ($ag -and (Get-Item $agentExe).LastWriteTime -gt $ag.StartTime) {
+    Stop-Process -Name agent -Force -ErrorAction SilentlyContinue
+    Start-Sleep -Milliseconds 800; $ag = $null
+}
+if (-not $ag) {
+    Start-Process $agentExe -ArgumentList "--port","47800","--code","t" -WindowStyle Hidden
+    Start-Sleep -Seconds 1
+}
+
+Write-Host "=== 1. connect form (V4 entry state) ==="
+[void](Adb-Shell @("am","force-stop","com.verify.remote"))
+[void](Adb-Shell @("am","start","-n","com.verify.remote/.MainActivity"))
+Start-Sleep -Seconds 3
+$ui = Get-Ui
+if ($ui -notmatch "android\.widget\.EditText") { throw "form fields missing" }
+Shot "4b-form.png"
+
+Write-Host "=== 2. failure path (V5): unreachable host via intent ==="
+[void](Adb-Shell @("am","force-stop","com.verify.remote"))
+[void](Adb-Shell @("am","start","-n","com.verify.remote/.MainActivity",
+    "--es","host","192.168.1.199","--ei","port","47800","--es","code","t"))
+# Measured 2026-10-30: an unreachable host returns to the form with a concrete
+# reason after ~32s (quinn's default connect timeout). Budget 50s, not 30s -
+# the earlier 30s budget made this step look like a failure when it was only
+# still inside the timeout. UX follow-up (logged in the result record): during
+# those 30s the panel says only "connecting" with no cancel affordance.
+$deadline = (Get-Date).AddSeconds(50)
+$err = ""
+while ((Get-Date) -lt $deadline) {
+    Start-Sleep -Milliseconds 1000
+    $ui = Get-Ui
+    if ($ui -match "android\.widget\.EditText") {
+        $shown = [regex]::Matches($ui, 'text="([^"]+)"') | ForEach-Object { $_.Groups[1].Value }
+        $err = $shown -join " | "
+        break
+    }
+}
+if ($err) { Shot "4b-v5-error.png" } else { throw "V5: never returned to form with an error" }
+Write-Host "  error state visible: yes"
+
+Write-Host "=== 3. live session (V4 via intent) ==="
+[void](Adb-Shell @("am","force-stop","com.verify.remote"))
+[void](Adb-Shell @("am","start","-n","com.verify.remote/.MainActivity",
+    "--es","host",$phoneIp,"--ei","port","47800","--es","code","t"))
+$ui = Wait-Live 25
+if (-not $ui) { throw "session never became live" }
+Shot "4b-connected-stream.png"
+Write-Host "  $([regex]::Match($ui,'text="([^"]*RTT=[^"]*)"').Groups[1].Value)"
+
+Write-Host "=== 4. keyboard shown (real IME bound to our InputConnection) ==="
+$btns = [regex]::Matches($ui, '<node[^>]*class="android\.widget\.Button"[^>]*bounds="\[(\d+),(\d+)\]\[(\d+),(\d+)\]"')
+if ($btns.Count -lt 1) { throw "no keyboard button" }
+$b0 = $btns[0]
+$kx = [int](([int]$b0.Groups[1].Value + [int]$b0.Groups[3].Value) / 2)
+$ky = [int](([int]$b0.Groups[2].Value + [int]$b0.Groups[4].Value) / 2)
+[void](Adb-Shell @("input","tap","$kx","$ky"))
+Start-Sleep -Seconds 3
+$ime = (Adb-Shell @("dumpsys","input_method")).out
+if ($ime -notmatch "mInputShown=true") { throw "IME not shown" }
+if ($ime -notmatch "mHaveConnection=true") { throw "no InputConnection bound" }
+Shot "4b-ime-shown.png"
+
+Write-Host "=== 5. IME commit reaches the pipeline (diagnostic shows commit) ==="
+[void](Adb-Shell @("input","text","hello"))
+Start-Sleep -Milliseconds 1200
+[void](Adb-Shell @("input","keyevent","62"))   # SPACE: accept any pending candidate
+Start-Sleep -Seconds 2
+$ui = Get-Ui
+$diag = [regex]::Match($ui, 'text="([^"]*RTT=[^"]*)"').Groups[1].Value
+Write-Host "  phone status: $diag"
+Shot "4b-ime-committed.png"
+
+Write-Host "=== 6. disconnect (back key) ==="
+[void](Adb-Shell @("input","keyevent","4"))    # dismiss keyboard
+Start-Sleep -Milliseconds 800
+[void](Adb-Shell @("input","keyevent","4"))    # disconnect
+Start-Sleep -Seconds 2
+$ui = Get-Ui
+if ($ui -match "RTT=") { throw "still connected after two BACK presses" }
+Shot "4b-disconnected.png"
+Write-Host "=== CAPTURE COMPLETE ==="
+Get-ChildItem $ev -Filter "4b-*.png" | ForEach-Object {
+    $b = [System.IO.File]::ReadAllBytes($_.FullName)
+    $sig = ($b[0..3] | ForEach-Object { $_.ToString("X2") }) -join " "
+    "{0,-28} {1,9} {2}" -f $_.Name, $b.Length, $sig
+}
diff --git a/tools/ime_commit_proof.ps1 b/tools/ime_commit_proof.ps1
new file mode 100644
index 0000000..37352a5
--- /dev/null
+++ b/tools/ime_commit_proof.ps1
@@ -0,0 +1,182 @@
+# 2b V6/V7 on-device IME path: does a real IME's commitText reach the remote
+# desktop? ASCII-only source (see personal lessons on PS 5.1 + BOM-less .ps1).
+#
+# Difference from phone_chain_proof.ps1: that one drives Activity.onKeyDown with
+# adb keyevents (IME hidden). Here the IME is SHOWN, so keys are consumed by the
+# input method and reach us only through RemoteInputConnection.commitText /
+# sendKeyEvent. That is the path Chinese candidates take, and it is the risk R1
+# item in the plan (vivo ROM + third-party IME behaviour was never observed).
+#
+# What this proves mechanically: IME is bound to our InputConnection and its
+# committed text lands in a Windows window we own, via protocol v3.
+# What it cannot prove: human candidate-list selection (needs a finger); see
+# the result record - V6/V7 full judgement is listed as manual acceptance.
+#
+# Usage:
+#   powershell -ExecutionPolicy Bypass -File tools\ime_commit_proof.ps1
+
+param(
+    [string]$PhoneIp = "192.168.1.180",
+    [int]$Port = 47800,
+    [string]$Code = "t",
+    [string]$Text = "hi"
+)
+$ErrorActionPreference = "Stop"
+$repo = (Resolve-Path "$PSScriptRoot\..").Path
+$adb  = "D:\working\android\sdk\platform-tools\adb.exe"
+$tmp  = "$env:TEMP\remote-ime-proof"
+
+New-Item -ItemType Directory -Force -Path $tmp | Out-Null
+$pidFile    = "$tmp\target.pid"
+$stopFile   = "$tmp\stop.flag"
+$resultFile = "$tmp\received.txt"
+Remove-Item $pidFile,$stopFile,$resultFile -ErrorAction SilentlyContinue
+
+Add-Type -TypeDefinition @"
+using System;
+using System.Runtime.InteropServices;
+public static class FgApi2 {
+  [DllImport("user32.dll")] public static extern IntPtr GetForegroundWindow();
+}
+"@
+
+function Adb {
+    param([Parameter(Mandatory)][string[]]$AdbArgs)
+    $old = $ErrorActionPreference
+    $ErrorActionPreference = "Continue"
+    try {
+        $out = & $adb @AdbArgs 2>$null
+        return @{ out = ($out -join "`n"); code = $LASTEXITCODE }
+    }
+    finally { $ErrorActionPreference = $old }
+}
+function Adb-Shell { param([Parameter(Mandatory)][string[]]$Cmd) return Adb -AdbArgs (@("shell") + $Cmd) }
+
+function Wait-File {
+    param([string]$Path, [int]$TimeoutMs = 20000)
+    $t = 0
+    while (-not (Test-Path $Path) -and $t -lt ($TimeoutMs / 150)) { Start-Sleep -Milliseconds 150; $t++ }
+    if (-not (Test-Path $Path)) { throw "timeout waiting for $Path" }
+}
+
+function Assert-Foreground([IntPtr]$hwnd, [string]$where) {
+    $deadline = (Get-Date).AddMilliseconds(2000)
+    while ((Get-Date) -lt $deadline) {
+        if ([FgApi2]::GetForegroundWindow() -eq $hwnd) { return }
+        Start-Sleep -Milliseconds 30
+    }
+    throw "$where : foreground=$([FgApi2]::GetForegroundWindow()) want=$($hwnd.ToInt64()) - refusing to inject"
+}
+
+function Get-PhoneUiText {
+    [void](Adb-Shell @("uiautomator", "dump", "/sdcard/ui.xml"))
+    $r = Adb -AdbArgs @("pull", "/sdcard/ui.xml", "$tmp\ui.xml")
+    if ($r.code -ne 0 -or -not (Test-Path "$tmp\ui.xml")) { return "" }
+    return [System.IO.File]::ReadAllText("$tmp\ui.xml", [System.Text.Encoding]::UTF8)
+}
+
+function Read-Received {
+    if (-not (Test-Path $resultFile)) { return "" }
+    $b = [System.IO.File]::ReadAllBytes($resultFile)
+    $s = [System.Text.Encoding]::UTF8.GetString($b)
+    if ($s.Length -gt 0 -and $s[0] -eq [char]0xFEFF) { $s = $s.Substring(1) }
+    return $s
+}
+
+Write-Host "=== 0. retire earlier targets (touch only existing stop flags) ==="
+$flags = @(Get-ChildItem -Path $env:TEMP -Recurse -Filter "stop.flag" -ErrorAction SilentlyContinue |
+    Where-Object { $_.FullName -like "*remote*proof*" })
+if ($flags.Count -gt 0) {
+    Write-Host "  retiring $($flags.Count)"
+    foreach ($f in $flags) { (Get-Item $f.FullName).LastWriteTime = Get-Date }
+    Start-Sleep -Seconds 3
+}
+
+Write-Host "=== 1. fresh target window ==="
+Start-Process powershell.exe -ArgumentList "-NoProfile","-ExecutionPolicy","Bypass",`
+    "-File","$repo\tools\text_target.ps1","-PidFile",$pidFile,`
+    "-ResultFile",$resultFile,"-StopFile",$stopFile,"-GrabForeground"
+Wait-File $pidFile
+$parts = @((Get-Content $pidFile -Raw) -split "`n")
+$tid = [int]$parts[0].Trim()
+$hwnd = [IntPtr][long]$parts[1].Trim()
+Assert-Foreground $hwnd "after launch"
+Write-Host "  target pid=$tid hwnd=$($hwnd.ToInt64())"
+
+Write-Host "=== 2. agent freshness + phone session ==="
+$agentExe = "$repo\target\release\agent.exe"
+$ag = Get-Process agent -ErrorAction SilentlyContinue
+if ($ag -and (Get-Item $agentExe).LastWriteTime -gt $ag.StartTime) {
+    Stop-Process -Name agent -Force -ErrorAction SilentlyContinue
+    Start-Sleep -Milliseconds 800; $ag = $null
+}
+if (-not $ag) {
+    Start-Process $agentExe -ArgumentList "--port",$Port,"--code",$Code -WindowStyle Hidden
+    Start-Sleep -Seconds 1
+}
+[void](Adb-Shell @("am", "force-stop", "com.verify.remote"))
+[void](Adb-Shell @("am", "start", "-n", "com.verify.remote/.MainActivity",
+    "--es", "host", $PhoneIp, "--ei", "port", "$Port", "--es", "code", $Code))
+$deadline = (Get-Date).AddSeconds(25)
+$xml = ""
+while ((Get-Date) -lt $deadline) { Start-Sleep -Milliseconds 900; $xml = Get-PhoneUiText; if ($xml -match "RTT=") { break } }
+if ($xml -notmatch "RTT=") { throw "phone did not connect" }
+Write-Host "  $([regex]::Match($xml,'text="([^"]*RTT=[^"]*)"').Groups[1].Value)"
+
+Write-Host "=== 3. show the soft keyboard (tap the app's keyboard button) ==="
+# Button coordinates come from the live hierarchy. Our remote-state bar adds
+# "keyboard" before "disconnect", so index 0 is the keyboard button - asserted
+# rather than assumed by checking the count and printing what we tapped.
+$btns = [regex]::Matches($xml, '<node[^>]*class="android\.widget\.Button"[^>]*bounds="\[(\d+),(\d+)\]\[(\d+),(\d+)\]"')
+if ($btns.Count -lt 1) { throw "no buttons found in remote state" }
+$b0 = $btns[0]
+$kx = [int](([int]$b0.Groups[1].Value + [int]$b0.Groups[3].Value) / 2)
+$ky = [int](([int]$b0.Groups[2].Value + [int]$b0.Groups[4].Value) / 2)
+Write-Host "  tapping first button ($kx,$ky)"
+[void](Adb-Shell @("input", "tap", "$kx", "$ky"))
+Start-Sleep -Seconds 3
+$ime = (Adb-Shell @("dumpsys", "input_method")).out
+$shown = ($ime -match "mInputShown=true")
+$bound = ($ime -match "mHaveConnection=true")
+$curId = [regex]::Match($ime, "mCurId=(\S+)").Groups[1].Value
+Write-Host "  IME: shown=$shown boundToUs=$bound cur=$curId"
+if (-not $shown) { throw "soft keyboard did not appear" }
+if (-not $bound) { throw "no InputConnection bound - our onCheckIsTextEditor/onCreateInputConnection path failed" }
+
+Write-Host "=== 4. type through the IME, expect commitText -> v3 Text -> Windows ==="
+$before = Read-Received
+Assert-Foreground $hwnd "before IME text"
+[void](Adb-Shell @("input", "text", $Text))
+Start-Sleep -Milliseconds 1500
+# Latin input in most Chinese IMEs commits without a candidate pick; if the IME
+# instead left it composing, nudge with SPACE to force a commit.
+$got = Read-Received
+if ($got -notmatch [regex]::Escape($Text)) {
+    Write-Host "  not committed yet (got [$got]); sending SPACE to accept candidate"
+    [void](Adb-Shell @("input", "keyevent", "62"))   # KEYCODE_SPACE
+    Start-Sleep -Milliseconds 1500
+    $got = Read-Received
+}
+Write-Host "  target received: [$got]  (expected to contain [$Text])"
+$diag = [regex]::Match((Get-PhoneUiText), 'text="([^"]*RTT=[^"]*)"').Groups[1].Value
+Write-Host "  phone status: $diag"
+if ($got -notmatch [regex]::Escape($Text)) {
+    throw "IME COMMIT FAIL: nothing from the IME reached the Windows target"
+}
+Write-Host "  PASS: real IME -> RemoteInputConnection -> v3 Text -> Windows window"
+
+Write-Host "=== 5. back key must close keyboard first, not the session ==="
+[void](Adb-Shell @("input", "keyevent", "4"))
+Start-Sleep -Seconds 2
+$ime2 = (Adb-Shell @("dumpsys", "input_method")).out
+$xml2 = Get-PhoneUiText
+$stillLive = ($xml2 -match "RTT=")
+$kbHidden = ($ime2 -match "mInputShown=false")
+Write-Host "  after BACK: session live=$stillLive keyboard hidden=$kbHidden"
+if (-not ($kbHidden -and $stillLive)) { throw "BACK did not behave as keyboard-first-then-session" }
+Write-Host "  PASS: first BACK dismissed the keyboard, session kept"
+
+Write-Host "=== 6. cleanup ==="
+New-Item -ItemType File -Force -Path $stopFile | Out-Null
+Start-Sleep -Milliseconds 500
+Write-Host "=== IME COMMIT PROOF COMPLETE ==="
diff --git a/tools/shot.ps1 b/tools/shot.ps1
new file mode 100644
index 0000000..bcab77f
--- /dev/null
+++ b/tools/shot.ps1
@@ -0,0 +1,23 @@
+# Byte-safe device screenshot helper.
+# ASCII-only. PS 5.1 `>` redirection writes UTF-16, which corrupts PNG bytes
+# (measured 2026-10-30: `adb exec-out screencap -p > x.png` produced a file
+# starting with FF FE). Capture on-device and pull instead.
+param(
+    [Parameter(Mandatory = $true)][string]$Out,
+    [string]$Device = "/sdcard/shot.png"
+)
+$ErrorActionPreference = "Stop"
+$adb = "D:\working\android\sdk\platform-tools\adb.exe"
+$old = $ErrorActionPreference
+$ErrorActionPreference = "Continue"
+try {
+    & $adb shell screencap -p $Device | Out-Null
+    if ($LASTEXITCODE -ne 0) { throw "screencap failed ($LASTEXITCODE)" }
+    & $adb pull $Device $Out | Out-Null
+    if ($LASTEXITCODE -ne 0) { throw "pull failed ($LASTEXITCODE)" }
+}
+finally { $ErrorActionPreference = $old }
+$b = [System.IO.File]::ReadAllBytes($Out)
+$sig = ($b[0..3] | ForEach-Object { $_.ToString("X2") }) -join " "
+if ($sig -ne "89 50 4E 47") { throw "not a PNG (sig=$sig): $Out" }
+Write-Host ("OK {0} ({1:N0} bytes)" -f (Split-Path $Out -Leaf), $b.Length)