Deepen process outcome policy

[dbrosio3]

This pull request introduces a new process outcome policy abstraction to standardize how command-line tool executions and their failures are handled throughout the codebase. The main changes include the addition of a new outcome-policy.ts module, refactoring of several modules to use this new abstraction, improvements to error reporting, and updates to tests to cover the new logic.

Process outcome policy abstraction:

• Added a new src/process/outcome-policy.ts module that provides a unified way to classify, represent, and format process execution outcomes, including handling of spawn errors, timeouts, exit codes, and signals. This includes new types (ProcessOutcome, ProcessFailure, etc.), a runProcessOutcome function, and a formatProcessFailure utility.

Refactoring to use process outcome policy:

• Updated src/ai/providers/run-provider-command.ts, src/runner/plugins/gitleaks.ts, and src/runner/tool-command.ts to use runProcessOutcome and related types/utilities instead of directly using runTimedCommand. This centralizes process result handling and error formatting, and simplifies the logic for interpreting command outcomes. [1] [2] [3] [4] [5] [6] [7] [8]

Error and failure reporting improvements:

• All modules now use formatProcessFailure to generate consistent, human-readable error messages for different failure types (spawn errors, timeouts, exit codes, signals), improving diagnostics for users and developers. [1] [2] [3] [4]

Configuration and naming consistency:

• Standardized and renamed constants for output capture/tail limits and kill grace period in src/process/timed-command.ts to use a consistent naming scheme, making configuration clearer and less error-prone. [1] [2]

Expanded test coverage:

• Updated and expanded tests in test/process.test.ts to cover the new process outcome policy logic, including all failure modes and message formatting, ensuring robustness of the new abstraction. [1] [2]