diff --git a/config/vitest.config.ts b/config/vitest.config.ts
index b3846c92cc2..be64fe0c24b 100644
--- a/config/vitest.config.ts
+++ b/config/vitest.config.ts
@@ -15,7 +15,12 @@ export default defineConfig({
   },
   test: {
     environment: 'node',
-    include: ['src/**/*.test.ts', 'src/**/*.test.tsx', 'config/scripts/**/*.test.mjs'],
+    include: [
+      'src/**/*.test.ts',
+      'src/**/*.test.tsx',
+      'config/scripts/**/*.test.mjs',
+      'tests/e2e/**/*.unit.test.ts'
+    ],
     // Why: the full suite runs heavy TS transforms plus real git/http fixtures;
     // the Vitest 5s defaults are too tight for the slowest integration cases.
     hookTimeout: 60_000,
diff --git a/tests/e2e/terminal-column-probes.ts b/tests/e2e/terminal-column-probes.ts
index 6e11151658c..0f8f0400bc7 100644
--- a/tests/e2e/terminal-column-probes.ts
+++ b/tests/e2e/terminal-column-probes.ts
@@ -8,6 +8,7 @@ import {
   waitForPtyShellEcho
 } from './terminal-pty-readiness'
 import { nodeTerminalCommand } from './terminal-node-command'
+import { buildFreshShellProbeInputSequence } from './terminal-probe-input-sequence'
 
 type TerminalColumnProbeWindow = Window & {
   __store?: {
@@ -78,21 +79,14 @@ export async function waitForPtyColumnsAtMost(
   while (Date.now() < deadline) {
     const marker = `ORCA_PTY_COLUMNS_${randomUUID()}`
     lastMarker = marker
-    // Why: a few CI shells occasionally eat the first printable byte when a
-    // command is written immediately after Ctrl+C/Ctrl+U. Split control bytes
-    // from the probe command so the shell sees the whole `node` executable.
-    await sendToTerminal(page, ptyId, '\x03')
-    await page.waitForTimeout(50)
-    await sendToTerminal(page, ptyId, '\x15')
-    await page.waitForTimeout(50)
-    await sendToTerminal(
-      page,
-      ptyId,
+    for (const input of buildFreshShellProbeInputSequence(
       `${nodeTerminalCommand([
         '-e',
         `console.log('${marker}:' + (process.stdout.columns || 0))`
       ])}\r`
-    )
+    )) {
+      await sendToTerminal(page, ptyId, input)
+    }
     const probeDeadline = Date.now() + Math.min(5_000, Math.max(0, deadline - Date.now()))
     while (Date.now() < probeDeadline) {
       const content = await getTerminalContentForPtyId(page, ptyId, 30_000)
diff --git a/tests/e2e/terminal-probe-input-sequence.ts b/tests/e2e/terminal-probe-input-sequence.ts
new file mode 100644
index 00000000000..85402078072
--- /dev/null
+++ b/tests/e2e/terminal-probe-input-sequence.ts
@@ -0,0 +1,5 @@
+export function buildFreshShellProbeInputSequence(command: string): readonly string[] {
+  // Why: Windows ConPTY can echo a startup Ctrl+C as literal "^C", which
+  // corrupts the following PowerShell command before the shell is ready.
+  return [command]
+}
diff --git a/tests/e2e/terminal-probe-input-sequence.unit.test.ts b/tests/e2e/terminal-probe-input-sequence.unit.test.ts
new file mode 100644
index 00000000000..41e2cd82504
--- /dev/null
+++ b/tests/e2e/terminal-probe-input-sequence.unit.test.ts
@@ -0,0 +1,12 @@
+import { describe, expect, it } from 'vitest'
+import { buildFreshShellProbeInputSequence } from './terminal-probe-input-sequence'
+
+describe('buildFreshShellProbeInputSequence', () => {
+  it('does not prefix fresh shell probes with interrupt or line-kill bytes', () => {
+    const command = "& 'C:\\node\\node.exe' '-e' 'console.log(1)'\r"
+
+    expect(buildFreshShellProbeInputSequence(command)).toEqual([command])
+    expect(buildFreshShellProbeInputSequence(command).join('')).not.toContain('\x03')
+    expect(buildFreshShellProbeInputSequence(command).join('')).not.toContain('\x15')
+  })
+})
diff --git a/tests/e2e/terminal-pty-readiness.ts b/tests/e2e/terminal-pty-readiness.ts
index 7991f305339..77bc7688346 100644
--- a/tests/e2e/terminal-pty-readiness.ts
+++ b/tests/e2e/terminal-pty-readiness.ts
@@ -3,6 +3,7 @@ import type { Page } from '@stablyai/playwright-test'
 import { expect } from '@stablyai/playwright-test'
 import { sendToTerminal } from './helpers/terminal'
 import { nodeTerminalCommand } from './terminal-node-command'
+import { buildFreshShellProbeInputSequence } from './terminal-probe-input-sequence'
 
 type TerminalPtyReadinessWindow = Window & {
   __paneManagers?: Map<
@@ -83,14 +84,11 @@ export async function waitForPtyShellEcho(
   const deadline = Date.now() + timeoutMs
   await waitForPtyPaneMounted(page, ptyId, Math.min(10_000, timeoutMs))
   while (Date.now() < deadline) {
-    await sendToTerminal(page, ptyId, '\x03')
-    await page.waitForTimeout(50)
-    await sendToTerminal(page, ptyId, '\x15')
-    await page.waitForTimeout(50)
-
     // Why: terminal scrollback includes command echo. Encode the marker inside
     // the node snippet so seeing the plain marker proves the shell executed it.
-    await sendToTerminal(page, ptyId, encodedMarkerCommand(marker))
+    for (const input of buildFreshShellProbeInputSequence(encodedMarkerCommand(marker))) {
+      await sendToTerminal(page, ptyId, input)
+    }
 
     const probeDeadline = Date.now() + Math.min(3_000, Math.max(0, deadline - Date.now()))
     while (Date.now() < probeDeadline) {