fix(lab): report frozen Sense Go toolchain [T-014]

Sense/scripts/t014-capacity.ps1

@@ -518,9 +518,10 @@ $ffmpegVersion = (& $script:ffmpeg -version 2>&1 | Select-Object -First 1)
 if ($ffmpegVersion -notmatch '^ffmpeg version 8\.1\.2') {
     throw 'T-014 requires the frozen FFmpeg 8.1.2 build'
 }
-$goVersion = (& go version 2>&1 | Out-String).Trim()
-if ($LASTEXITCODE -ne 0 -or $goVersion -notmatch '^go version go1\.23\.') {
-    throw 'T-014 requires the frozen Go 1.23 toolchain'
+$senseDirectory = Join-Path $script:repoRoot 'Sense'
+$goVersion = (& go '-C' $senseDirectory 'version' 2>&1 | Out-String).Trim()
+if ($LASTEXITCODE -ne 0 -or $goVersion -notmatch '^go version go1\.26\.5 ') {
+    throw 'T-014 requires the frozen Sense Go 1.26.5 toolchain'
 }
 
 $systemTemp = [IO.Path]::GetFullPath([IO.Path]::GetTempPath()).TrimEnd('\')
@@ -633,7 +634,7 @@ $failure = $null
 $resultJSON = $null
 try {
     Invoke-Checked $script:ffmpeg '-hide_banner' '-loglevel' 'error' '-f' 'lavfi' '-i' 'testsrc2=size=640x360:rate=10' '-t' '30' '-c:v' 'libx264' '-preset' 'ultrafast' '-tune' 'zerolatency' '-pix_fmt' 'yuv420p' '-g' '10' '-an' '-movflags' '+faststart' '-y' $script:fixturePath
-    Invoke-Checked 'go' '-C' (Join-Path $script:repoRoot 'Sense') 'build' '-o' $senseBinary './cmd/sense-api'
+    Invoke-Checked 'go' '-C' $senseDirectory 'build' '-o' $senseBinary './cmd/sense-api'
 
     $stage = 'starting isolated PostgreSQL'
     New-Item -ItemType Directory -Path $pgData | Out-Null

tests/test_sense_capacity_contract.py

@@ -38,6 +38,8 @@ class SenseCapacityContractTests(unittest.TestCase):
         self.assertIn("Wait-Convergence 'enabled'", self.script)
         self.assertIn("Wait-Convergence 'disabled'", self.script)
         self.assertIn("maximum_unconverged", self.script)
+        self.assertIn("go1\\.26\\.5", self.script)
+        self.assertIn("& go '-C' $senseDirectory 'version'", self.script)
 
     def test_isolated_postgres_and_cleanup_are_guarded(self):
         for migration in range(2, 12):