Fix timeout implementation and address review feedback

- Kill git process on timeout: use child_process.spawn directly for
  timeout-eligible operations so we have a ChildProcess handle to send
  SIGTERM (then SIGKILL after 5s). On Windows, SIGTERM is a forced kill
  so the SIGKILL fallback is effectively a no-op there.

- Fix timeout:0 not working: replace falsy || coalescion with explicit
  empty-string check so that '0' is not replaced by the default '300'.

- Refactor execGit to use an options object instead of 5 positional
  parameters, eliminating error-prone filler args (false, false, {}).

- Pass allowAllExitCodes through to execGitWithTimeout so both code
  paths have consistent behavior for non-zero exit codes.

- Add settled guard to prevent double-reject when both close and error
  events fire on the spawned process.

- Handle null exit code (process killed by signal) as an error rather
  than silently treating it as success.

- Capture stderr in error messages for the timeout path, matching the
  information level of the non-timeout exec path.

- Log SIGKILL failures at debug level instead of empty catch block.

- Warn on customListeners being ignored in the timeout path.

- Emit core.warning() when invalid input values are silently replaced
  with defaults, so users know their configuration was rejected.

- Add input validation in setTimeout (reject negative values).

- Clarify retry-max-attempts semantics: total attempts including the
  initial attempt (3 = 1 initial + 2 retries).

- Remove Kubernetes probe references from descriptions.

- Use non-exhaustive list (e.g.) for network operations in docs to
  avoid staleness if new operations are added.

- Add tests for timeout/retry input parsing (defaults, timeout:0,
  custom values, invalid input with warnings, backoff clamping) and
  command manager configuration (setTimeout, setRetryConfig, fetch).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

action.yml

@@ -97,21 +97,20 @@ inputs:
     default: true
   timeout:
     description: >
-      Timeout in seconds for each git network operation attempt (fetch, lfs-fetch, ls-remote).
-      If a single attempt exceeds this, it is killed and retried.
+      Timeout in seconds for each git network operation attempt (e.g. fetch, lfs-fetch, ls-remote).
+      If a single attempt exceeds this, the process is terminated.
+      If retries are configured (see retry-max-attempts), the operation will be retried.
       Set to 0 to disable. Default is 300 (5 minutes).
-      Similar to Kubernetes probe timeoutSeconds.
     default: 300
   retry-max-attempts:
     description: >
-      Maximum number of retry attempts for failed git network operations.
-      Similar to Kubernetes probe failureThreshold.
+      Total number of attempts for each git network operation (including the initial attempt).
+      For example, 3 means one initial attempt plus up to 2 retries.
     default: 3
   retry-min-backoff:
     description: >
       Minimum backoff time in seconds between retry attempts.
       The actual backoff is randomly chosen between min and max.
-      Similar to Kubernetes probe periodSeconds.
     default: 10
   retry-max-backoff:
     description: >