add CI tests for openhands-getting-started playbook

[harkgill-amd]

Addresses #601.

Added tests for openhands CI following test patterns from existing playbooks (most notable n8ns and other lemonade based playbooks).

Temporarily forcing uv install through CI tests to ensure consistency across all runners.

  ┌──────────────────────────┬───────────────────────────┬──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
  │ Test ID (×linux/windows) │           Step            │                                                                  What it validates                                                                   │
  ├──────────────────────────┼───────────────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ prereq-clis-*            │ Prerequisites             │ lemonade, node, npm, uv all present                                                                                                                  │
  ├──────────────────────────┼───────────────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ lemonade-chat-*          │    Verify the Local Model │ Lemonade /api/v1/models responds; model is present + downloaded; deterministic "Reply with exactly: OK" chat (temperature:0, max_tokens:32) succeeds │
  ├──────────────────────────┼───────────────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ agent-canvas-install-*   │    Install                │ npm install -g @openhands/agent-canvas succeeds (user-owned npm prefix on Linux, no root needed)                                                     │
  ├──────────────────────────┼───────────────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ agent-canvas-version-*   │    Install                │ agent-canvas CLI is on PATH (--version, falling back to --help)                                                                                      │
  ├──────────────────────────┼───────────────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ agent-canvas-server-*    │    Launch                 │ Server starts, http://127.0.0.1:8000/ returns HTTP 200, then the process is killed cleanly (frees the shared runner)                                 │
  ├──────────────────────────┼───────────────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ lemonade-unload-*        │ Cleanup                   │ lemonade unload frees the GPU pool for the next job                                                                                                  │
  └──────────────────────────┴───────────────────────────┴──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

[harkgill-amd]

Hey @neubig, our Windows CI runners are failing to execute the playbook commands with the below logs from the agent-canvas step,

  [1/2] Checking prerequisites... 
  [2/2] Starting services...
  [agent-server] Starting on port 18000...
  [agent-server] Using PyPI (1.36.1, default)
  [agent-server] The system cannot find the file specified.
  [agent-server] Exited with code 1                                  
  [agent-server] Timeout waiting for http://localhost:18000/server_info after 60s
  [agent-server] Last error: fetch failed
  [secrets] Skipping secret seeding - agent-server not ready
  [automation] Building litellm==1.93.0
  [automation] × Failed to build `litellm==1.93.0`
  [automation]   ╰─▶ Call to `maturin.build_wheel` failed (exit code: 1)
  [automation]       Rust not found, installing into a temporary directory

The frontend comes up but the agent-server backend never starts due to a missing litellm dependency. Noticing the documentation at https://github.com/OpenHands/openhands#quickstart points to a docker based setup for Windows systems. Do we want to go this route for the playbook as well or is there a recommended solution for the environment setup issues seen on a native Windows install?