Add CLI integration tests for `find` and `resolve` commands

[karthiknadig]

Summary

We have end-to-end tests for the JSONRPC server (see crates/pet/tests/e2e_performance.rs and related test files), but no integration tests for the CLI find and resolve commands. We need CLI tests that exercise the same binary via std::process::Command, similar to how the server tests spawn the pet process.

Scope

Test 1: find --json basic output validation

• Run pet find --json
• Parse stdout as JSON
• Validate the structure has managers and environments arrays
• Validate each environment has required fields (executable, kind, etc.)

Test 2: resolve --json output validation

• Run pet find --json, pick an executable from the results
• Run pet resolve <exe> --json
• Parse stdout as JSON
• Validate the resolved environment has a version field populated
• Validate executable matches what was passed in

Test 3: find --kind filtering

• Run pet find --kind <known_kind> --json
• Validate all returned environments match the specified kind

Test 4: find --workspace scoping

• Run pet find --workspace --json with a known directory
• Validate only workspace-scoped environments are returned

Test 5: CLI args + env var equivalence (after #353)

• Run pet find --conda-executable /path/to/conda --json
• Run PET_CONDA_EXECUTABLE=/path/to/conda pet find --json
• Validate both produce the same results
• Validate CLI flag takes precedence over env var when both are set

Test 6: Glob expansion in search paths (after #354)

• Create temp directories matching a glob pattern
• Run pet find '/tmp/test_*/venv' --json (quoted glob)
• Validate the glob was expanded and environments were searched in matching directories

Implementation approach

• Create crates/pet/tests/cli_test.rs
• Use std::process::Command to spawn ./target/debug/pet (same pattern as e2e_performance.rs)
• Use the ci feature flag for tests that need a real Python on PATH
• Parse JSON output with serde_json
• Use assert_cmd crate if desired, but std::process::Command is sufficient

Example test skeleton

#[test]
#[cfg(feature = "ci")]
fn find_json_output_is_valid() {
    let output = Command::new(env!("CARGO_BIN_EXE_pet"))
        .args(["find", "--json"])
        .output()
        .expect("failed to run pet");

    assert!(output.status.success());
    let result: Value = serde_json::from_slice(&output.stdout)
        .expect("stdout is not valid JSON");
    assert!(result["environments"].is_array());
    assert!(result["managers"].is_array());
}

#[test]
#[cfg(feature = "ci")]
fn resolve_json_output_has_version() {
    // First find an environment
    let find_output = Command::new(env!("CARGO_BIN_EXE_pet"))
        .args(["find", "--json"])
        .output()
        .expect("failed to run pet find");
    let found: Value = serde_json::from_slice(&find_output.stdout).unwrap();
    let exe = found["environments"][0]["executable"].as_str().unwrap();

    // Then resolve it
    let resolve_output = Command::new(env!("CARGO_BIN_EXE_pet"))
        .args(["resolve", exe, "--json"])
        .output()
        .expect("failed to run pet resolve");

    assert!(resolve_output.status.success());
    let resolved: Value = serde_json::from_slice(&resolve_output.stdout).unwrap();
    assert!(resolved["version"].is_string());
}

Depends on

• Add missing CLI arguments for find and resolve commands (with env var fallbacks) #353 (for env var tests)
• Add glob pattern expansion to CLI find search paths and environment directories #354 (for glob expansion tests)

Tests for the base find --json and resolve --json can land independently.