test(v0.7): add comprehensive unit tests for Kraftfile v0.7 parser

[alok-108]

Summary

Adds unit tests for the Kraftfile v0.7 schema parser introduced in #2776. This PR ensures correctness of parsing, error handling, and round-trip serialization.

Changes

• Created pkg/app/schema/v0.7/parser_test.go with table-driven tests.
• • Added testdata/ directory containing sample Kraftfiles (minimal, full, invalid, wrong version).
• • Tests cover:
• • Minimal valid config
• • Full config with all fields
• • Invalid YAML syntax
• • Rejection of wrong version (e.g., v0.6)
• • Round-trip consistency

Motivation

Comprehensive tests are essential for the new parser to be merged confidently. They validate the implementation against the v0.7 spec and prevent regressions.

Related Issue

Contributes to #2682

Testing Done

• Tests pass locally when integrated with the types defined in feat: Add Kraftfile schema v0.7 support #2776.
• • No changes to production code.

Notes for Reviewers

This PR is complementary to #2776 and does not modify any existing logic.
Dependency: This PR builds on the types defined in #2776. It should be merged into the pr-2776 branch first, or reviewed alongside it. Once #2776 is merged, this test suite can be directly integrated.