v0.2.1

Model discovery

AgentShell can now ask every supported CLI which models it currently advertises:

models = await shell.list_models(cwd="/path/to/project")
response = await shell.execute(
    cwd="/path/to/project",
    prompt="Review this project",
    model=models[0],
)

The returned strings are passed unchanged to execute(model=...) and stream(model=...).
Discovery is account/workspace-aware, sends no inference prompt, imports no harness SDK, and
uses no static fallback catalog.

Supported discovery paths:

• Claude Code stream-JSON initialization
• opencode models
• Copilot CLI headless JSON-RPC
• codex debug models
• pi --no-approve --list-models
• cursor-agent models

Reliability

• Added timeout, cancellation, malformed-output, and UTF-8 error handling.
• Discovery subprocesses use an isolated live process-group sentinel, preventing both leaked
  descendants and signalling through a reaped/reused CLI PID.
• Pi selectors are provider-qualified so duplicate model IDs remain unambiguous.
• Harness ordering and aliases such as auto and default are preserved.

Documentation and tests

• Updated the README, AgentShell skill, architecture notes, and agent parameter comparison.
• Added parser, integration, process-lifecycle, selector pass-through, and real-CLI E2E tests.
• 726 unit/integration tests pass, all six model-discovery E2Es pass, and the full local E2E
  suite was verified before release.