fix: Windows Chrome extraction and debugging environment (#1088)

* windows debugging

* fixes

* fixes

* fix: handle Windows path separators in Chrome zip extraction

The zip crate's enclosed_name() normalizes paths to use backslashes on
Windows, but extract_zip used split_once('/') which only matches forward
slashes. This caused Chrome to be extracted into a nested chrome-win64/
subdirectory instead of directly into the version directory.

Also adds debug diagnostics to find_installed_chrome() (gated behind
AGENT_BROWSER_DEBUG) and better error messages when Chrome cache exists
but no binary is found.

Fixes #1076

* feat: add Puppeteer browser cache as Chrome fallback

Search ~/.cache/puppeteer/chrome/ (or PUPPETEER_CACHE_DIR) for Chrome
binaries before falling back to Playwright's cache. Puppeteer v19+
stores Chrome for Testing in this location, so users with an existing
Puppeteer install can use agent-browser without a separate install step.

* fmt

AGENTS.md

@@ -66,6 +66,68 @@ cd cli && cargo fmt -- --check   # Check formatting
 cd cli && cargo clippy            # Lint
 ```
 
+## Windows Debugging
+
+A remote Windows Server 2022 EC2 instance is available for debugging Windows-specific issues. It uses AWS Systems Manager (SSM) -- no SSH, no open ports. Commands run via `aws ssm send-command` and return stdout/stderr.
+
+### Prerequisites
+
+The instance must be provisioned first (one-time, by a human):
+
+```bash
+./scripts/windows-debug/provision.sh
+```
+
+Requires: AWS CLI v2 configured with `ec2:*`, `iam:CreateRole`, `iam:AttachRolePolicy`, `ssm:SendCommand`, `ssm:GetCommandInvocation` permissions and a default VPC.
+
+### Usage
+
+Start the instance (if stopped):
+
+```bash
+./scripts/windows-debug/start.sh
+```
+
+Run a command on Windows:
+
+```bash
+./scripts/windows-debug/run.sh "<powershell-command>"
+```
+
+Sync the current git branch and rebuild:
+
+```bash
+./scripts/windows-debug/sync.sh
+```
+
+Stop the instance when done (avoids cost):
+
+```bash
+./scripts/windows-debug/stop.sh
+```
+
+### Common Workflows
+
+Run unit tests on Windows:
+
+```bash
+./scripts/windows-debug/run.sh "cd C:\agent-browser && cargo test --manifest-path cli\Cargo.toml"
+```
+
+Run e2e tests on Windows:
+
+```bash
+./scripts/windows-debug/run.sh "cd C:\agent-browser && cargo test e2e --manifest-path cli\Cargo.toml -- --ignored --test-threads=1"
+```
+
+Check bootstrap progress (first boot only):
+
+```bash
+./scripts/windows-debug/run.sh "Get-Content C:\bootstrap.log"
+```
+
+The repo lives at `C:\agent-browser` on the instance. Rust, Git, and Chrome are pre-installed. The `run.sh` wrapper automatically adds cargo and git to PATH.
+
 <!-- opensrc:start -->
 
 ## Source Code Reference