fix(windows): harden installation and parent cancellation

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
         run: cargo test --workspace --locked
 
   windows-daemon:
-    name: Windows daemon and update regression tests
+    name: Windows daemon, installer and cancellation regression tests
     runs-on: windows-latest
 
     steps:
@@ -55,8 +55,16 @@ jobs:
       - name: Run Windows update tests
         run: cargo test -p bsk --lib --locked cli::update::tests
 
-      - name: Run Windows update process tests
-        run: cargo test -p bsk --test windows_update --locked
+      - name: Run Windows update and cancellation process tests
+        run: cargo test -p bsk --test windows_update --test windows_parent_cancel --locked
+
+      - name: Run installer tests (Windows PowerShell 5.1)
+        shell: powershell
+        run: ./scripts/install-windows.test.ps1
+
+      - name: Run installer tests (PowerShell 7)
+        shell: pwsh
+        run: ./scripts/install-windows.test.ps1
 
   frontend:
     name: Frontend lint, typecheck, tests, build

crates/bsk-cli/src/cli/business_rpc.rs

@@ -73,6 +73,14 @@ where
     P: Serialize + Send + 'static,
     R: DeserializeOwned + Send + 'static,
 {
+    let parent_cancel = stdin_cancellation();
+    if parent_cancel.as_ref().is_some_and(|rx| *rx.borrow()) {
+        return Err(CliError::from_rpc(RpcError {
+            code: ErrorCode::Cancelled,
+            message: "parent closed the cancellation pipe".into(),
+            data: None,
+        }));
+    }
     let rpc_id: RpcId = format!("{}-{}", rpc_id_prefix, random_short_id());
     let mut client = IpcClient::connect(sock.clone()).await?;
     let rpc_id_for_call = rpc_id.clone();
@@ -88,16 +96,16 @@ where
     let outcome = tokio::select! {
         biased;
         res = &mut main_fut => res?,
-        sig = wait_for_sigint() => {
-            sig.context("install SIGINT handler").map_err(CliError::Local)?;
-            debug!(rpc_id = %rpc_id_for_cancel, "SIGINT: forwarding cancel to daemon");
+        sig = wait_for_cancel(parent_cancel) => {
+            sig.context("wait for cancellation").map_err(CliError::Local)?;
+            debug!(rpc_id = %rpc_id_for_cancel, "forwarding cancel to daemon");
             let _ = send_cancel(&sock, &rpc_id_for_cancel).await;
             match tokio::time::timeout(CANCEL_RESPONSE_GRACE, &mut main_fut).await {
                 Ok(res) => res?,
                 Err(_) => {
                     debug!(
                         rpc_id = %rpc_id_for_cancel,
-                        "SIGINT: cancel grace elapsed; synthesising cancelled error"
+                        "cancel grace elapsed; synthesising cancelled error"
                     );
                     return Err(CliError::from_rpc(RpcError {
                         code: ErrorCode::Cancelled,
@@ -146,8 +154,57 @@ fn random_short_id() -> String {
     bytes.iter().map(|b| format!("{b:02x}")).collect()
 }
 
-/// Wait for either Ctrl-C or process SIGTERM. Returning here means
-/// the user has asked us to stop.
+/// Opt-in control pipe for parent processes that cannot send Ctrl-C (Node on
+/// Windows). One reader survives the short-lived runtimes used by multi-RPC
+/// commands such as upload. Ordinary CLI stdin and terminal Ctrl-C are unchanged.
+fn stdin_cancellation() -> Option<tokio::sync::watch::Receiver<bool>> {
+    if std::env::var("BSK_CANCEL_ON_STDIN_CLOSE").as_deref() != Ok("1") {
+        return None;
+    }
+    static CANCEL: std::sync::OnceLock<tokio::sync::watch::Receiver<bool>> =
+        std::sync::OnceLock::new();
+    Some(
+        CANCEL
+            .get_or_init(|| {
+                let (tx, rx) = tokio::sync::watch::channel(false);
+                std::thread::spawn(move || {
+                    use std::io::Read;
+                    let mut stdin = std::io::stdin().lock();
+                    let mut buf = [0; 64];
+                    loop {
+                        match stdin.read(&mut buf) {
+                            Ok(0) => break,
+                            Ok(_) => {}
+                            Err(err) if err.kind() == std::io::ErrorKind::Interrupted => continue,
+                            Err(_) => break,
+                        }
+                    }
+                    let _ = tx.send(true);
+                });
+                rx
+            })
+            .clone(),
+    )
+}
+
+async fn wait_for_cancel(
+    parent_cancel: Option<tokio::sync::watch::Receiver<bool>>,
+) -> anyhow::Result<()> {
+    let parent_closed = async move {
+        match parent_cancel {
+            Some(mut rx) => {
+                let _ = rx.wait_for(|closed| *closed).await;
+            }
+            None => std::future::pending::<()>().await,
+        }
+    };
+    tokio::select! {
+        result = wait_for_sigint() => result,
+        _ = parent_closed => Ok(()),
+    }
+}
+
+/// Wait for terminal Ctrl-C.
 async fn wait_for_sigint() -> anyhow::Result<()> {
     tokio::signal::ctrl_c().await.context("listen for SIGINT")?;
     Ok(())

crates/bsk-cli/tests/windows_parent_cancel.rs

@@ -0,0 +1,163 @@
+//! Real Windows CLI processes cancel over IPC when their parent closes stdin.
+#![cfg(windows)]
+
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use bsk::daemon::info::DaemonInfo;
+use bsk_protocol::{ErrorCode, Frame, Method, ResponseBody, ResponseFrame, RpcError};
+use serde_json::json;
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
+use tokio::net::windows::named_pipe::ServerOptions;
+use tokio::process::Command;
+use tokio::sync::{Notify, watch};
+
+#[tokio::test]
+async fn stdin_close_cancels_single_and_multi_rpc_commands_but_is_opt_in() {
+    for mode in ["wait", "upload", "ordinary"] {
+        let home = tempfile::tempdir().unwrap();
+        let pipe_name = format!(r"\\.\pipe\bsk-parent-cancel-{}", uuid::Uuid::new_v4());
+        let info = DaemonInfo::now(std::process::id(), (&pipe_name).into(), 0, "0.2.0");
+        std::fs::write(
+            home.path().join("daemon.json"),
+            serde_json::to_vec(&info).unwrap(),
+        )
+        .unwrap();
+        let mut pipe = ServerOptions::new()
+            .first_pipe_instance(true)
+            .create(&pipe_name)
+            .unwrap();
+        let registered = Arc::new(Notify::new());
+        let pending = Arc::new(Mutex::new(None::<String>));
+        let (cancel, cancelled) = watch::channel(false);
+        let ready = Arc::clone(&registered);
+        let name = pipe_name.clone();
+        let server = tokio::spawn(async move {
+            let mut connections = tokio::task::JoinSet::new();
+            loop {
+                pipe.connect().await.unwrap();
+                let next = ServerOptions::new().create(&name).unwrap();
+                let connection = std::mem::replace(&mut pipe, next);
+                let ready = Arc::clone(&ready);
+                let pending = Arc::clone(&pending);
+                let cancel = cancel.clone();
+                let mut cancelled = cancelled.clone();
+                let name = name.clone();
+                connections.spawn(async move {
+                    let (read, mut write) = tokio::io::split(connection);
+                    let mut reader = BufReader::new(read);
+                    let mut line = String::new();
+                    while reader.read_line(&mut line).await.unwrap_or(0) > 0 {
+                        let Frame::Request(req) = serde_json::from_str::<Frame>(&line).unwrap()
+                        else {
+                            panic!("expected request");
+                        };
+                        line.clear();
+                        let body = match req.method {
+                            Method::SystemStatus => ResponseBody::Ok(json!({
+                                "daemon_version": "0.2.0", "protocol_version": "1.1",
+                                "pid": std::process::id(), "uptime_secs": 0,
+                                "ws_port": 0, "sock_path": name,
+                                "browsers": [], "sessions": [], "version_skew_browsers": []
+                            })),
+                            Method::TransferBegin => ResponseBody::Ok(json!({
+                                "transfer_id": "fixture", "chunk_size": 512
+                            })),
+                            Method::ToolWaitMs if mode == "ordinary" => {
+                                ResponseBody::Ok(json!({"waited_ms": 1}))
+                            }
+                            Method::ToolWaitMs | Method::TransferChunk => {
+                                *pending.lock().unwrap() = Some(req.id.clone());
+                                ready.notify_one();
+                                cancelled.wait_for(|value| *value).await.unwrap();
+                                ResponseBody::Err(RpcError {
+                                    code: ErrorCode::Cancelled,
+                                    message: "parent cancellation reached daemon".into(),
+                                    data: None,
+                                })
+                            }
+                            Method::Cancel => {
+                                let target =
+                                    req.params.as_ref().unwrap()["rpc_id"].as_str().unwrap();
+                                assert_eq!(pending.lock().unwrap().as_deref(), Some(target));
+                                cancel.send(true).unwrap();
+                                ResponseBody::Ok(json!({"cancelled": true}))
+                            }
+                            other => panic!("unexpected request after cancellation: {other:?}"),
+                        };
+                        let response = Frame::Response(ResponseFrame { id: req.id, body });
+                        let mut bytes = serde_json::to_vec(&response).unwrap();
+                        bytes.push(b'\n');
+                        if write.write_all(&bytes).await.is_err() {
+                            break;
+                        }
+                    }
+                });
+            }
+        });
+
+        let mut cmd = Command::new(env!("CARGO_BIN_EXE_bsk"));
+        cmd.env("BSK_HOME", home.path())
+            .env("BSK_AUTO_UPDATE", "off")
+            .env_remove("BSK_CANCEL_ON_STDIN_CLOSE")
+            .stdout(std::process::Stdio::piped())
+            .stderr(std::process::Stdio::piped())
+            .creation_flags(0x0800_0000)
+            .kill_on_drop(true);
+        if mode == "upload" {
+            let source = home.path().join("upload.txt");
+            std::fs::write(&source, b"upload fixture").unwrap();
+            cmd.args([
+                "upload",
+                "--session",
+                "fixture",
+                "--selector",
+                "input",
+                "--file",
+            ])
+            .arg(source);
+        } else {
+            cmd.args(["wait-ms", if mode == "ordinary" { "1ms" } else { "60s" }]);
+        }
+        cmd.arg("--json");
+        if mode == "ordinary" {
+            cmd.stdin(std::process::Stdio::null());
+        } else {
+            cmd.env("BSK_CANCEL_ON_STDIN_CLOSE", "1")
+                .stdin(std::process::Stdio::piped());
+        }
+        let mut child = cmd.spawn().unwrap();
+        if mode != "ordinary" {
+            tokio::time::timeout(Duration::from_secs(10), registered.notified())
+                .await
+                .expect("CLI registered business RPC");
+            // Normal stdin bytes are not a cancellation; only closing the pipe is.
+            child
+                .stdin
+                .as_mut()
+                .unwrap()
+                .write_all(b"still connected")
+                .await
+                .unwrap();
+            drop(child.stdin.take());
+        }
+        let output = tokio::time::timeout(Duration::from_secs(5), child.wait_with_output())
+            .await
+            .expect("CLI must settle promptly")
+            .unwrap();
+        server.abort();
+        let _ = server.await;
+        assert_eq!(
+            output.status.code(),
+            Some(if mode == "ordinary" { 0 } else { 2 }),
+            "{mode}: stdout={} stderr={}",
+            String::from_utf8_lossy(&output.stdout),
+            String::from_utf8_lossy(&output.stderr)
+        );
+        if mode != "ordinary" {
+            let body: serde_json::Value = serde_json::from_slice(&output.stdout).unwrap();
+            assert_eq!(body["code"], "cancelled");
+            assert_eq!(body["message"], "parent cancellation reached daemon");
+        }
+    }
+}

install.ps1

@@ -21,6 +21,7 @@ $ErrorActionPreference = "Stop"
 
 $Repo = if ($env:BSK_REPO) { $env:BSK_REPO } else { "Tencent/BrowserSkill" }
 $InstallDir = if ($env:BSK_INSTALL_DIR) { $env:BSK_INSTALL_DIR } else { Join-Path $HOME ".local\bin" }
+$InstallDir = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($InstallDir)
 $GitHub = "https://github.com/${Repo}"
 
 function Write-Log {
@@ -64,7 +65,7 @@ function Get-PlatformTriple {
 function Add-ToUserPath {
     param([string]$Dir)
 
-    $currentUserPath = [Environment]::GetEnvironmentVariable("PATH", "User") -split ";" | Where-Object { $_ }
+    $currentUserPath = @([Environment]::GetEnvironmentVariable("PATH", "User") -split ";" | Where-Object { $_ })
 
     if ($currentUserPath -contains $Dir) {
         Write-Log "$Dir is already in your user PATH"
@@ -90,30 +91,59 @@ function Add-ToSessionPath {
 # ── Git Bash (bash environment) PATH helper ──────────────────────────────────
 
 function Add-ToBashProfile {
-    param([string]$Dir)
+    param([string]$Dir, [string]$BashRc = (Join-Path $HOME ".bashrc"))
 
     # Convert Windows path (e.g. C:\Users\foo\.local\bin) to Git-Bash Unix-style (/c/Users/foo/.local/bin)
     $unixPath = $Dir -replace '\\', '/'
     if ($unixPath -match '^([A-Z]):(.*)$') {
         $unixPath = '/' + $matches[1].ToLower() + $matches[2]
     }
-    $bashRc = Join-Path $HOME ".bashrc"
-    $exportLine = "export PATH=""${unixPath}:`$PATH""  # bsk CLI"
+    # Single-quote the literal directory; only the existing PATH is expanded.
+    $shellQuote = "'" + [char]34 + "'" + [char]34 + "'"
+    $quotedPath = "'" + $unixPath.Replace("'", $shellQuote) + "'"
+    $exportLine = "export PATH=${quotedPath}:`"`$PATH`"  # bsk CLI"
 
-    if (Test-Path $bashRc) {
-        $content = Get-Content $bashRc -Raw -ErrorAction SilentlyContinue
-        if ($content -match [regex]::Escape($unixPath)) {
+    if (Test-Path -LiteralPath $BashRc) {
+        $content = [System.IO.File]::ReadAllText($BashRc)
+        if ($content.Contains($exportLine)) {
             Write-Log "$unixPath is already in ~/.bashrc"
             return
         }
     }
 
-    Add-Content $bashRc "`n$exportLine" -Encoding ASCII
+    # Explicit BOM-less UTF-8 also works in Windows PowerShell 5.1.
+    [System.IO.File]::AppendAllText($BashRc, "`n$exportLine`n", (New-Object System.Text.UTF8Encoding($false)))
     Write-Log "added ${unixPath} to ~/.bashrc"
 }
 
 # ── Main ──────────────────────────────────────────────────────────────────────
 
+# Stage on the destination volume before stopping the daemon. Never truncate
+# the installed executable: failed replacement must leave it usable.
+function Install-Binary {
+    param([string]$Source, [string]$Target)
+
+    $staged = "$Target.install-$([Guid]::NewGuid().ToString('N'))"
+    try {
+        [System.IO.File]::Copy($Source, $staged)
+        if ([System.IO.File]::Exists($Target)) {
+            # Use the downloaded CLI: older versions have broken Windows
+            # liveness checks. Stop verifies daemon identity before terminating it.
+            & $Source daemon stop
+            if ($LASTEXITCODE -ne 0) { throw "could not stop bsk daemon; existing installation was not replaced" }
+            # PowerShell 5.1 converts $null to an empty path for string parameters.
+            [System.IO.File]::Replace($staged, $Target, [NullString]::Value)
+            Write-Log "daemon will restart automatically on the next browser command"
+        }
+        else {
+            [System.IO.File]::Move($staged, $Target)
+        }
+    }
+    finally {
+        if ([System.IO.File]::Exists($staged)) { [System.IO.File]::Delete($staged) }
+    }
+}
+
 function Main {
     $platform = Get-PlatformTriple
 
@@ -184,7 +214,7 @@ function Main {
             New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
         }
 
-        Copy-Item -Path (Join-Path $tempDir "bsk.exe") -Destination (Join-Path $InstallDir "bsk.exe") -Force
+        Install-Binary -Source (Join-Path $tempDir "bsk.exe") -Target (Join-Path $InstallDir "bsk.exe")
 
         Write-Log "installed bsk to $InstallDir\bsk.exe"
 
@@ -199,12 +229,8 @@ function Main {
 
         # Verify
         $bskPath = Join-Path $InstallDir "bsk.exe"
-        if (Get-Command bsk -ErrorAction SilentlyContinue) {
-            & bsk --version
-        }
-        else {
-            Write-Log "verify install: & ""$bskPath"" --version"
-        }
+        & $bskPath --version
+        if ($LASTEXITCODE -ne 0) { throw "installed bsk failed verification" }
 
         Write-Log "done"
         Write-Host ""

packages/dsh-plugin-browserskill/src/runner.ts

@@ -5,7 +5,7 @@
  * map the CLI's JSON error envelope onto a thrown `BskError`.
  */
 
-import { type ChildProcess, spawn } from "node:child_process";
+import { type ChildProcess, type SpawnOptionsWithoutStdio, spawn } from "node:child_process";
 
 /** Shape of the JSON error envelope `bsk --json` prints on failure. */
 export interface BskErrorBody {
@@ -53,7 +53,11 @@ export interface BskRunOptions {
 }
 
 /** Minimal spawn signature so tests can substitute a fake child process. */
-export type SpawnImpl = (command: string, args: string[]) => ChildProcess;
+export type SpawnImpl = (
+  command: string,
+  args: string[],
+  options?: SpawnOptionsWithoutStdio,
+) => ChildProcess;
 
 export interface BskRunner {
   /** Run `bsk <args...> --json` and collect its output. */
@@ -64,29 +68,65 @@ export interface BskRunner {
   killFor(tag: string): number;
 }
 
-// Business RPCs translate SIGINT into the daemon's cancel(rpc_id) protocol.
-// Give that bounded reconciliation path time to settle before the hard kill.
+// Business RPCs translate Ctrl-C / opt-in stdin EOF into cancel(rpc_id).
+// Allow reconciliation before hard-killing an old or unresponsive CLI.
 const KILL_GRACE_MS = 3000;
+// Windows IPC may spend 5s connecting, then 2s cancelling and 2s settling.
+const WINDOWS_KILL_GRACE_MS = 10_000;
 const SESSION_BUSY_RETRY_DELAY_MS = 100;
 
 export function createBskRunner(bskPath: string, spawnImpl: SpawnImpl = spawn): BskRunner {
   const live = new Map<ChildProcess, string | undefined>();
+  const windows = process.platform === "win32";
+  const cancelling = new Set<ChildProcess>();
 
   function killChild(child: ChildProcess): void {
-    if (child.exitCode !== null || child.signalCode !== null) return;
-    child.kill("SIGINT");
-    const force = setTimeout(() => {
+    if (child.exitCode !== null || child.signalCode !== null || cancelling.has(child)) return;
+    cancelling.add(child);
+    // Node kills Windows children outright for SIGINT. EOF asks the CLI to
+    // send its existing cancel RPC and wait for browser reconciliation.
+    if (windows && child.stdin) child.stdin.end();
+    else child.kill("SIGINT");
+    const force = setTimeout(
+      () => {
         if (child.exitCode === null && child.signalCode === null) child.kill("SIGKILL");
-    }, KILL_GRACE_MS);
+      },
+      windows ? WINDOWS_KILL_GRACE_MS : KILL_GRACE_MS,
+    );
     force.unref();
+    child.once("close", () => {
+      clearTimeout(force);
+      cancelling.delete(child);
+    });
   }
 
   return {
     run(args, options = {}) {
+      if (options.signal?.aborted) {
+        return Promise.resolve({
+          code: null,
+          stdout: "",
+          stderr: "",
+          timedOut: false,
+          aborted: true,
+        });
+      }
       return new Promise<BskRunResult>((resolve, reject) => {
         let child: ChildProcess;
         try {
-          child = spawnImpl(bskPath, [...args, "--json"]);
+          child = spawnImpl(
+            bskPath,
+            [...args, "--json"],
+            windows
+              ? {
+                  windowsHide: true,
+                  env: { ...process.env, BSK_CANCEL_ON_STDIN_CLOSE: "1" },
+                }
+              : undefined,
+          );
+          // A child exiting while cancellation closes stdin may report EPIPE.
+          // Its close/error event remains the authority for the run result.
+          child.stdin?.on("error", () => {});
         } catch (error) {
           reject(error);
           return;

packages/dsh-plugin-browserskill/tests/runner.test.ts

@@ -1,6 +1,7 @@
 import type { ChildProcess } from "node:child_process";
 import { EventEmitter } from "node:events";
-import { describe, expect, it } from "vitest";
+import { PassThrough } from "node:stream";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import {
   type BskRunResult,
   createBskRunner,
@@ -92,6 +93,75 @@ describe("createBskRunner", () => {
   });
 });
 
+describe("Windows parent cancellation", () => {
+  const originalPlatform = Object.getOwnPropertyDescriptor(process, "platform")!;
+  beforeEach(() => Object.defineProperty(process, "platform", { value: "win32" }));
+  afterEach(() => {
+    Object.defineProperty(process, "platform", originalPlatform);
+    vi.useRealTimers();
+  });
+
+  it("opts in to stdin cancellation and waits for CLI reconciliation", async () => {
+    const child = Object.assign(new FakeChild(), { stdin: new PassThrough() });
+    const spawn = vi.fn(() => child as unknown as ChildProcess);
+    const runner = createBskRunner("bsk", spawn);
+    const abort = new AbortController();
+    const result = runner.run(["snapshot"], { signal: abort.signal });
+    expect(spawn.mock.calls[0]).toEqual([
+      "bsk",
+      ["snapshot", "--json"],
+      {
+        windowsHide: true,
+        env: { ...process.env, BSK_CANCEL_ON_STDIN_CLOSE: "1" },
+      },
+    ]);
+    abort.abort();
+    expect(child.stdin.writableEnded).toBe(true);
+    expect(child.killedWith).toEqual([]);
+    // Closing an already-exited child's pipe must not crash the host.
+    child.stdin.emit("error", Object.assign(new Error("closed"), { code: "EPIPE" }));
+    child.finish(2, '{"code":"cancelled"}');
+    expect(await result).toMatchObject({ code: 2, aborted: true });
+  });
+
+  it("bounds cancellation of an old or unresponsive CLI", async () => {
+    vi.useFakeTimers();
+    const child = Object.assign(new FakeChild(), { stdin: new PassThrough() });
+    const runner = createBskRunner("bsk", fakeSpawn([child]));
+    const result = runner.run(["snapshot"], { timeoutMs: 5 });
+    await vi.advanceTimersByTimeAsync(5);
+    expect(child.stdin.writableEnded).toBe(true);
+    expect(child.killedWith).toEqual([]);
+    await vi.advanceTimersByTimeAsync(10_000);
+    expect(child.killedWith).toEqual(["SIGKILL"]);
+    expect(await result).toMatchObject({ timedOut: true });
+  });
+
+  it("cancels only the requested tag and clears the fallback after exit", async () => {
+    vi.useFakeTimers();
+    const a = Object.assign(new FakeChild(), { stdin: new PassThrough() });
+    const b = Object.assign(new FakeChild(), { stdin: new PassThrough() });
+    const runner = createBskRunner("bsk", fakeSpawn([a, b]));
+    const first = runner.run(["snapshot"], { tag: "a" });
+    const second = runner.run(["snapshot"], { tag: "b" });
+    expect(runner.killFor("a")).toBe(1);
+    expect(a.stdin.writableEnded).toBe(true);
+    expect(b.stdin.writableEnded).toBe(false);
+    a.finish(2);
+    b.finish(0);
+    await Promise.all([first, second]);
+    expect(vi.getTimerCount()).toBe(0);
+  });
+
+  it("does not start work for an already-aborted call", async () => {
+    const spawn = vi.fn();
+    const runner = createBskRunner("bsk", spawn);
+    const signal = AbortSignal.abort();
+    expect(await runner.run(["snapshot"], { signal })).toMatchObject({ aborted: true });
+    expect(spawn).not.toHaveBeenCalled();
+  });
+});
+
 describe("parseBskJson", () => {
   const base: BskRunResult = { code: 0, stdout: "", stderr: "", timedOut: false, aborted: false };
 

scripts/install-windows.test.ps1

@@ -0,0 +1,135 @@
+#Requires -Version 5.1
+param([string]$BskPath = (Join-Path $PSScriptRoot "../target/debug/bsk.exe"))
+$ErrorActionPreference = "Stop"
+
+# Load definitions, never Main: no downloads or changes to the real user PATH.
+$installer = Join-Path $PSScriptRoot "../install.ps1"
+$tokens = $null
+$errors = $null
+$ast = [System.Management.Automation.Language.Parser]::ParseFile($installer, [ref]$tokens, [ref]$errors)
+if ($errors.Count) { throw ($errors | Out-String) }
+foreach ($statement in $ast.EndBlock.Statements) {
+    if ($statement -is [System.Management.Automation.Language.FunctionDefinitionAst]) {
+        $definition = $statement.Extent.Text
+        if ($statement.Name -eq "Add-ToUserPath") {
+            $definition = $definition.Replace('[Environment]::GetEnvironmentVariable("PATH", "User")', '$script:UserPath')
+            $definition = $definition.Replace('[Environment]::SetEnvironmentVariable("PATH", $newUserPath, "User")', '$script:UserPath = $newUserPath')
+        }
+        Invoke-Expression $definition
+    }
+}
+function Assert-Equal($Actual, $Expected) {
+    if ($Actual -cne $Expected) { throw "expected [$Expected], got [$Actual]" }
+}
+function Assert-Fails([scriptblock]$Action) {
+    $failed = $false
+    try { & $Action } catch { $failed = $true }
+    if (-not $failed) { throw "expected failure" }
+}
+
+$dir = 'C:\Users\Alice\.local\bin'
+foreach ($existing in @('', 'C:\WindowsApps', 'C:\A;C:\B')) {
+    $script:UserPath = $existing
+    Add-ToUserPath $dir
+    $expected = if ($existing) { "$existing;$dir" } else { $dir }
+    Assert-Equal $script:UserPath $expected
+    Add-ToUserPath $dir
+    Assert-Equal $script:UserPath $expected
+}
+
+$root = Join-Path ([IO.Path]::GetTempPath()) ("bsk-install-test-" + [Guid]::NewGuid().ToString('N'))
+[IO.Directory]::CreateDirectory($root) | Out-Null
+$oldBskHome = $env:BSK_HOME
+$oldAutoUpdate = $env:BSK_AUTO_UPDATE
+$daemon = $null
+try {
+    $utf8 = New-Object System.Text.UTF8Encoding($false)
+    $bashRc = Join-Path $root ".bashrc"
+    $existing = "# existing 中文 configuration" + [char]10
+    [IO.File]::WriteAllText($bashRc, $existing, $utf8)
+    $special = 'C:\Users\张三 space $HOME $(echo unsafe) ! & [x] O''Brien\.local\bin'
+    Add-ToBashProfile $special $bashRc
+    $first = [IO.File]::ReadAllText($bashRc)
+    if (-not $first.StartsWith($existing)) { throw "existing bashrc content changed" }
+    if (-not $first.Contains('张三')) { throw "Unicode path was lost" }
+    Add-ToBashProfile $special $bashRc
+    Assert-Equal ([IO.File]::ReadAllText($bashRc)) $first
+    $bytes = [IO.File]::ReadAllBytes($bashRc)
+    if ($bytes[0] -eq 0xEF) { throw "unexpected UTF-8 BOM" }
+
+    $bash = [IO.Path]::GetFullPath((Join-Path (Split-Path (Get-Command git).Source -Parent) "../bin/bash.exe"))
+    if (-not (Test-Path -LiteralPath $bash)) { throw "Git Bash is required for quoting regression" }
+    $env:BSK_TEST_RC = $bashRc
+    $probe = Join-Path $root 'probe.sh'
+    [IO.File]::WriteAllText($probe, 'source "$BSK_TEST_RC"; printf "%s\n" "${PATH%%:*}"', $utf8)
+    $actual = & $bash --noprofile --norc $probe
+    if ($LASTEXITCODE -ne 0) { throw "Git Bash failed" }
+    Assert-Equal $actual ('/c' + $special.Substring(2).Replace('\', '/'))
+
+    $env:BSK_HOME = Join-Path $root "home"
+    $env:BSK_AUTO_UPDATE = "off"
+    [IO.Directory]::CreateDirectory($env:BSK_HOME) | Out-Null
+    $sourceDir = Join-Path $root "download"
+    [IO.Directory]::CreateDirectory($sourceDir) | Out-Null
+    $source = Join-Path $sourceDir "bsk.exe"
+    [IO.File]::Copy((Resolve-Path -LiteralPath $BskPath).Path, $source)
+    $targetDir = Join-Path $root "中文 space [x] & install"
+    [IO.Directory]::CreateDirectory($targetDir) | Out-Null
+    $target = Join-Path $targetDir "bsk.exe"
+    Install-Binary $source $target
+    Assert-Equal (Get-FileHash -LiteralPath $target).Hash (Get-FileHash -LiteralPath $source).Hash
+
+    $daemon = Start-Process -FilePath $target -ArgumentList @('daemon', 'start', '--foreground', '--port', '0') -WindowStyle Hidden -PassThru
+    $infoPath = Join-Path $env:BSK_HOME "daemon.json"
+    $deadline = [DateTime]::UtcNow.AddSeconds(15)
+    while (-not [IO.File]::Exists($infoPath)) {
+        if ($daemon.HasExited -or [DateTime]::UtcNow -gt $deadline) { throw "daemon failed to start" }
+        Start-Sleep -Milliseconds 50
+    }
+    # PE overlays distinguish old/new executables without another build.
+    $stream = [IO.File]::OpenWrite($source)
+    try {
+        $stream.Seek(0, [IO.SeekOrigin]::End) | Out-Null
+        $marker = $utf8.GetBytes("installer replacement regression")
+        $stream.Write($marker, 0, $marker.Length)
+    } finally { $stream.Dispose() }
+    Install-Binary $source $target
+    if (-not $daemon.WaitForExit(5000)) { throw "old daemon still running" }
+    Assert-Equal (Get-FileHash -LiteralPath $target).Hash (Get-FileHash -LiteralPath $source).Hash
+    & $target --version
+    if ($LASTEXITCODE -ne 0) { throw "replacement is not executable" }
+
+    # Refuse replacement when daemon identity cannot be verified.
+    [IO.File]::WriteAllText($infoPath, 'invalid daemon metadata')
+    $before = (Get-FileHash -LiteralPath $target).Hash
+    Assert-Fails { Install-Binary $source $target }
+    Assert-Equal (Get-FileHash -LiteralPath $target).Hash $before
+    [IO.File]::Delete($infoPath)
+
+    # A remaining lock must fail without truncation or staging debris.
+    $lock = [IO.File]::Open($target, [IO.FileMode]::Open, [IO.FileAccess]::Read, [IO.FileShare]::None)
+    try { Assert-Fails { Install-Binary $source $target } } finally { $lock.Dispose() }
+    Assert-Equal (Get-FileHash -LiteralPath $target).Hash $before
+    if (@(Get-ChildItem -LiteralPath $targetDir -Filter "*.install-*").Count) { throw "staging files leaked" }
+    Write-Host "Windows installer regressions passed ($($PSVersionTable.PSVersion))"
+}
+catch {
+    Write-Host ($_ | Out-String)
+    Write-Host $_.ScriptStackTrace
+    throw
+}
+finally {
+    if ($daemon -and -not $daemon.HasExited) {
+        Stop-Process -Id $daemon.Id -Force
+        $daemon.WaitForExit(5000) | Out-Null
+    }
+    $env:BSK_HOME = $oldBskHome
+    $env:BSK_AUTO_UPDATE = $oldAutoUpdate
+    Remove-Item Env:BSK_TEST_RC -ErrorAction SilentlyContinue
+    # Resolve and verify before recursive cleanup; only this fixture is removed.
+    $resolvedRoot = [IO.Path]::GetFullPath($root)
+    $tempRoot = [IO.Path]::GetFullPath([IO.Path]::GetTempPath()).TrimEnd('\') + '\'
+    if (-not $resolvedRoot.StartsWith($tempRoot, [StringComparison]::OrdinalIgnoreCase) -or
+        -not ([IO.Path]::GetFileName($resolvedRoot)).StartsWith('bsk-install-test-')) { throw "invalid cleanup path" }
+    Remove-Item -LiteralPath $resolvedRoot -Recurse -Force
+}