fix: emit valid multiline string defaults for CRD models

[officialasishkumar]

fix invalid KCL generation for CRD string defaults that contain embedded newlines.

• emit triple-quoted KCL literals for multiline string defaults in generated schema bodies
• keep schema docstrings safe by rendering multiline defaults with escaped \n sequences instead of nested triple quotes
• add unit coverage for multiline string rendering and a CRD end-to-end regression test covering the reported reproducer

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• N
• Y

fix #150

2. What is the scope of this PR (e.g. component or file name):

pkg/swagger/generator/language.go
pkg/swagger/generator/template_repo.go
pkg/swagger/generator/templates/propertydoc.gotmpl
pkg/swagger/generator/templates/docstring.gotmpl
pkg/swagger/generator/support_test.go
pkg/swagger/generator/template_repo_test.go

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

More details:

• the current generator always emits regular quoted strings for defaults, which produces invalid KCL when the source default contains literal newlines
• this update keeps the generated assignment valid while preserving readable schema docs
• the new regression test exercises the CRD flow end to end with the multiline default from the issue report

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

Test coverage:

• go test ./pkg/swagger/generator -run 'Test(ToKCLValue|ToKCLDocValue|Generate_CRD2KCL_MultilineStringDefault)'
• go test ./...

[officialasishkumar]

PTAL @Peefy

[coveralls]

Pull Request Test Coverage Report for Build 24009554990

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 14 of 17 (82.35%) changed or added relevant lines in 1 file are covered.
• 132 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-3.6%) to 62.682%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/swagger/generator/language.go	14	17	82.35%

Files with Coverage Reduction	New Missed Lines	%
pkg/utils/integrate_gen.go	132	0.0%

Totals
Change from base Build 22742151113:	-3.6%
Covered Lines:	2234
Relevant Lines:	3564

---

💛 - Coveralls