Fix missing exit code check for streaming prepare command

[jsk11235]

The streaming version of run_stream() did not return exit code information, so the prepare command in DefaultProvider would proceed even if the command failed with non-zero exit code.

Changes:

• Add ExitCode(i32) variant to OutputLine enum
• Modify ShellConnector::run_stream() to yield exit code after stdout/stderr complete
• Check exit code in DefaultProvider::from_config() and return ProviderError::ExecFailed if prepare command fails
• Handle new ExitCode variant in output callbacks

🤖 Generated with Claude Code

[github-actions]

Vet found 4 issues.

---

[documentation_implementation_mismatch] (severity 3/5) (confidence 0.95)

The doc example for run_stream in the module-level documentation of src/connector.rs shows a match on OutputLine with only Stdout and Stderr variants, but the enum now has an ExitCode variant. The example would fail to compile due to non-exhaustive match.

[documentation_implementation_mismatch] (severity 3/5) (confidence 0.95)

The with_output_callback method's doc example in src/orchestrator/runner.rs shows a match with only Stdout and Stderr variants, missing the new ExitCode variant. This would fail to compile.

---

src/provider.rs:426

[documentation_implementation_mismatch] (severity 3/5) (confidence 0.95)

The doc example for stream_output in src/provider.rs shows a match on OutputLine with only Stdout and Stderr variants, but the enum now has an ExitCode variant. This example would fail to compile due to non-exhaustive match.

---

src/connector.rs:423

[test_coverage] (severity 2/5) (confidence 0.85)

The new ExitCode variant and the exit code streaming behavior in ShellConnector::run_stream() are not covered by any tests. A test should verify that run_stream yields an ExitCode item after stdout/stderr, and that the exit code value is correct for both successful and failing commands.

[github-actions]

Vet found 3 issues.

---

[correctness_syntax_issues] (severity 3/5) (confidence 0.95)

The Connector trait's run_stream doc example in src/connector.rs shows a match on OutputLine with only Stdout and Stderr arms. With the new ExitCode variant, this example would fail to compile due to non-exhaustive match.

---

src/connector.rs:179

[documentation_implementation_mismatch] (severity 3/5) (confidence 0.97)

The docstring for the run_stream method on the Connector trait says 'The stream does not provide the exit code. If you need the exit code, use run instead...' but the implementation now yields OutputLine::ExitCode as the last item in the stream. The doc comment should be updated to reflect that the stream now includes the exit code.

---

src/orchestrator/runner.rs:73

[correctness_syntax_issues] (severity 3/5) (confidence 0.95)

The OutputCallback type doc example in src/orchestrator/runner.rs shows a match on OutputLine with only Stdout and Stderr arms, but the enum now has an ExitCode variant. This doc example would fail to compile due to non-exhaustive match.