fix(rules): route Kotlin script files to Kotlin review rules

[Qiyuanqiii]

Description

Summary

• Route review-eligible .kt and .kts files to the existing built-in kotlin.md review rules.
• Align the default Kotlin test-path exclusion so .kts files under src/test/** are excluded in the same way as .kt files.
• Add deterministic resolver, extension, and exclusion regression coverage.
• Keep the rule mapping documentation synchronized across the English, Chinese, Japanese, Korean, and Russian locales.
• Integrate the follow-up contribution from @wu21-web in Qiyuanqiii/open-code-review#13.

Root Cause and Integrated Fix

OpenCodeReview uses separate configuration layers for file reviewability, default exclusions, and built-in rule selection:

1. supported_file_types.json already allows both .kt and .kts.
2. default_exclude_patterns.json previously excluded **/src/test/**/*.kt, but not the corresponding .kts files.
3. system_rules.json previously mapped only **/*.{kt} to kotlin.md.

That produced two inconsistencies:

• A review-eligible Kotlin script outside the default test exclusion passed the extension filter but fell back to default.md.
• A Kotlin script under src/test/** remained reviewable even though the equivalent .kt test source was excluded by default.

Path	Behavior before this change	Behavior after this change
app.kt	Reviewed with kotlin.md	Reviewed with kotlin.md
scripts/setup.kts	Reviewed with default.md	Reviewed with kotlin.md
src/test/kotlin/FooTest.kt	Excluded by default	Excluded by default
src/test/kotlin/scripts/FooTest.kts	Reviewed with default.md	Excluded by default

Rule Routing

The built-in Kotlin mapping now covers both extensions:

- "**/*.{kt}": "kotlin.md"
+ "**/*.{kt,kts}": "kotlin.md"

TestResolve_DefaultRules resolves scripts/setup.kts and requires the Kotlin-specific Null Safety guidance. The existing .kt case remains in place.

Default Exclusion Parity

The existing Kotlin test-source exclusion now covers Kotlin scripts as well:

- "**/src/test/**/*.kt"
+ "**/src/test/**/*.{kt,kts}"

The allowlist regression table explicitly covers .kt, .KT, .kts, and .KTS. Exclusion cases verify that a nested .kts file under src/test/** is excluded while a .kts file under src/main/** remains eligible.

Collaboration

• @wu21-web identified the default-exclusion inconsistency and contributed the allowlist and exclusion regression coverage through Qiyuanqiii/open-code-review#13.
• Integration commit ca6052117224978853d56f1194dcbb3d3f970f8b preserves their GitHub authorship and includes Co-authored-by: wu21-web <wu2196674@icloud.com>.

Compatibility and Scope

• Existing .kt rule resolution and default test exclusion are unchanged.
• Review-eligible .kts files now receive the already-shipped Kotlin rules instead of the generic default rules.
• .kts files under src/test/** are now excluded by default, matching the existing .kt behavior.
• Custom, project, and global rules retain their existing precedence for files that enter review.
• The contents of kotlin.md are unchanged.
• No public API, CLI, configuration schema, parser, supported-extension allowlist, or production Go implementation changes are introduced.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactoring (no functional changes)
• Documentation update
• CI / Build / Tooling

How Has This Been Tested?

Validation Environment

• Host: Windows 11 Pro, build 26200, amd64
• Go: go1.26.5 windows/amd64
• Node.js: v24.14.0
• Baseline: eda25482c74dff2f03bed2648497f23c512effe9 (origin/main)
• Original routing commit: b69402f9b0be7ae0ad916a61c259f14a5c75305b
• Integrated head: ca6052117224978853d56f1194dcbb3d3f970f8b

GNU Make is exposed as mingw32-make on this host. The unchanged Makefile targets were run with Git Bash and its Unix tools on PATH.

Regression Coverage

• The resolver test fails on the baseline because scripts/setup.kts falls through to default.md, which lacks the asserted Null Safety guidance.
• The updated mapping resolves both .kt and .kts paths to kotlin.md.
• Extension tests cover lowercase and uppercase .kt and .kts inputs.
• Exclusion tests distinguish src/test/kotlin/scripts/FooTest.kts from src/main/kotlin/scripts/Foo.kts.

Final Validation

• make check passed on the integrated patch: license headers, English-only validation, go mod tidy, gofmt -s -w ., and go vet
• Full make test passed with the race detector across every non-extension Go package
• make coverage passed at 90.9% overall; internal/config/allowlist was 88.9% and internal/config/rules was 91.7%
• git add --renormalize . introduced no unrelated line-ending changes
• git diff --check passed
• Required OCR self-review completed with 0 findings (session f512adf9-0dd5-46fa-8825-42a09f94c0dc)
• Current-head GitHub checks passed: CI, Windows, all cross-compilation targets, CodeQL, Pages, translation sync, and CLA

OCR Coverage

OCR selected default_exclude_patterns.json and reported 0 findings. allowed_ext_test.go was skipped by the repository's default test-path filter, so the OCR result is not presented as coverage of both contributed files; the test change was reviewed directly and exercised by the full race-test and coverage runs.

Checklist

• My code follows the project's coding style (go fmt, go vet)
• I have performed a self-review of the integrated change
• I have added tests that prove the routing and exclusion behavior
• New and existing unit tests pass locally with the integrated change
• I have updated the rule mapping documentation across all maintained locales
• Contributor authorship is preserved
• I have signed the CLA

Known Limitations

• Review-eligible .kts files reuse the existing Kotlin rules; this change does not add separate Gradle Kotlin DSL guidance.
• The default exclusion expansion is limited to the existing src/test/** Kotlin convention and does not introduce new test-directory patterns.
• This does not change rule precedence or the general rule-resolution mechanism.

Related Issues and Contributions

Closes #1090.

Includes Qiyuanqiii/open-code-review#13 by @wu21-web.

[github-actions]

✅ OpenCodeReview: Review complete: 0 finding(s) across 1 selected item(s).

[wu21-web]

Can I review this?

[Qiyuanqiii]

我可以复习一下吗？

sure

[wu21-web]

Some suggestion are out of range and cannot be put in the diff, I have submitted a pull request instead:
Qiyuanqiii#13

[Qiyuanqiii]

有些建议超出范围，无法放入差异，我已提交了拉取请求：启源qiii#13

Thanks for the follow‑up. I see that this PR addresses default exclusion parity for Kotlin test scripts, while #1091 is narrowly scoped to routing .kts files to the existing Kotlin rules. Since this changes file‑selection behavior, I think it would be better to keep it separate for independent review. What are your thoughts?

[wu21-web]

Actually I thought about routing .kts to kotlin.md few days ago, but I think it is unnesscary.
Since you restarted this idea, I won't oppose it.
Changes are minimal, and in my opinion both ways are OK.
It is fine you want to split this into 2 jobs. Up to you.

[Qiyuanqiii]

其实我几天前也想过把 .kts 路由到那个地方，但我觉得这不太必要。既然你重新提起了这个想法，我就不反对了。变化很小，我认为两种方式都可以。你想把这份工作分成两个工作没问题。随你决定。kotlin.md

我是想分两个，你觉得麻烦的话我也可以合并了然后修改一下pr描述（）

[wu21-web]

我肯定觉得麻烦的，我自己的pr他还一个都没处理
还有我的修改如果有漏洞，你自己修改一下我的分支谢谢

[Qiyuanqiii]

@wu21-web Thanks for the follow-up contribution. I merged #13 into this branch, updated the PR description to cover both rule routing and default exclusion parity, and preserved your authorship and co-author credit in commit ca60521. I also reran make check, make test, make coverage, and the required OCR self-review on the integrated patch; all current-head GitHub checks are passing.

[wu21-web]

Note sure if the rule docs need an update, but we might skip it for now.