test: add unit tests for project-utils utility functions

[yogeshwaran-c]

What kind of change does this PR introduce?

Test coverage improvement.

What is the current behavior?

The lib/utils/project-utils.ts file exports 6 utility functions that are used across multiple actions (generate, build, start) but has zero test coverage. These functions handle critical logic around:

• Whether to prompt users for project selection in monorepo mode
• Whether to generate spec files based on CLI flags and configuration hierarchy
• Whether to generate flat file structures
• Spec file suffix resolution
• Project list ordering for interactive prompts
• Option flag validation

What is the new behavior?

Adds a comprehensive test suite (test/lib/utils/project-utils.spec.ts) with 38 unit tests covering all 6 exported functions:

Function	Tests	Key scenarios
shouldAskForProject	9	All excluded schematics (app, sub-app, library, lib), undefined/empty projects, appName provided
shouldGenerateSpec	8	CLI priority (specPassedAsInput), boolean config, schematic-specific config objects, project-level fallback to global config
shouldGenerateFlat	4	CLI priority, configuration boolean, default false behavior
getSpecFileSuffix	4	CLI priority, config value, default "spec" fallback
moveDefaultProjectToStart	5	Project reordering, null/empty projects, sourceRoot-based filtering, defaultLabel stripping
hasValidOptionFlag	8	Boolean/string value matching, missing options, false value matching, empty arrays

All 38 tests pass. No existing tests are affected.

Additional context

• Follows the existing test patterns used in extra-args-warning.spec.ts and get-value-or-default.spec.ts
• Uses the same jest-config.json configuration
• No mocks needed -- all tested functions are pure or use already-tested helpers