Add changeset for --no-interactive flag fix

* fix(cli): respect --no-interactive flag in validate command

The validate command's spinner was starting regardless of the
--no-interactive flag, causing hangs in pre-commit hooks.

Changes:
- Pass noInteractive option to runBulkValidation
- Handle Commander.js --no-* flag syntax (sets interactive=false)
- Only start ora spinner when in interactive mode
- Add CI environment variable check to isInteractive() for industry
  standard compliance

* test: add unit tests for interactive utilities and CLI flag

- Export resolveNoInteractive() helper for reuse
- Add InteractiveOptions type export for testing
- Refactor validate.ts to use resolveNoInteractive()
- Add 17 unit tests for isInteractive() and resolveNoInteractive()
- Add CLI integration test for --no-interactive flag

This prevents future regressions where Commander.js --no-* flag
parsing is not properly handled.

.changeset/fix-no-interactive.md

@@ -0,0 +1,5 @@
+---
+"@fission-ai/openspec": patch
+---
+
+Fix `--no-interactive` flag in validate command to properly disable spinner, preventing hangs in pre-commit hooks and CI environments