Add reserved-port exclusions to getFreePorts

[yiguodev]

Summary

getFreePorts(count, excludePorts?)
  validate count and excluded port numbers
  bind localhost TCP listeners
  skip excluded and already-selected ports
  release all listeners on success or failure

• Add optional excludePorts to the Invoke payload while keeping API version 3 and the existing data.ports response.
• Keep listeners open throughout selection, including rejected ports, to prevent duplicate results and repeated allocation of an excluded port.
• Reject invalid exclusions and impossible counts; document behavior in English and Chinese.

Evidence

• Before (source): callers could only specify a count, and each listener closed before the next port was selected.
  After: deterministic tests verify exclusions, distinct ports, listener lifetime and cleanup on errors, invalid inputs, and zero-count behavior. Invoke tests cover omitted fields, duplicate exclusions, and malformed payloads.
• go test ./... -count=1 — passed on macOS.
• git diff --check origin/main...HEAD — passed.
• Native packaging and device integration were not rerun for this PR preparation.

Merge Danger

Door: two-way

No persistent data changes. Direct Go callers must adopt nodep.GetFreePorts(count, excludePorts) and pass nil when no exclusions are needed; the JSON field remains optional.

Blast Radius: API

Port selection temporarily holds TCP listeners until the batch completes. Returned ports are candidates, not reservations, and UDP availability is not checked.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.