feat(commithelper-go): add extends support for remote config inheritance

[kyungmi]

Summary

Adds extends support to @naverpay/commithelper-go, closing the feature gap with the Node.js version (@naverpay/commit-helper).

Closes #82

Motivation

Teams with multiple repositories want to maintain a single shared .commithelperrc.json (branch-prefix rules, protect lists, Jira passthrough) in a central place and override only project-specific rules locally.

Before:

// each repo must duplicate all shared rules
{
    "protect": ["main"],
    "rules": {
        "plan": "org/plan",
        "security": "Security/Security",
        "paymoney-plan": "Product-Planning/Paymoney_Plan"
        // ... 20+ more repeated across every repo
    }
}

After (remote URL):

{
    "extends": "https://raw.githubusercontent.com/my-org/.github/main/.commithelperrc.json",
    "rules": {
        "my-feature": "my-org/my-repo"
    }
}

After (local file path — for private registries):

{
    "extends": "./node_modules/@my-org/commithelperrc/.commithelperrc.json",
    "rules": {
        "my-feature": "my-org/my-repo"
    }
}

Install a shared config package as a dev dependency and reference it via local path. Works offline, versioned through package.json, no auth required — useful when your config is hosted on a private registry.

Changes

main.go

• Config struct: add Extends *string json:"extends,omitempty"``
• loadExtendsConfig(extends string) (Config, error): dispatches to HTTP fetch or local file read
• fetchExtendsConfig(url string) (Config, error): fetches a remote config via HTTP/HTTPS
  • 10-second timeout via http.Client
  • Non-200 responses and invalid JSON are fatal errors
• readLocalConfig(filePath string) (Config, error): reads a local file path
  • Relative paths resolved from current working directory (repo root)
• mergeConfigs(base, local Config) Config: merge strategy
  • rules: base is the default; local overrides on key conflict
  • protect: union of base + local (deduped, base order preserved)
  • passthrough: union of base + local (deduped, base order preserved)
  • template: local wins; falls back to base if local is unset
• loadConfig(): apply extends after local parse; nested extends are not followed

schema.json

• Add extends property (URL or local file path, no pattern restriction)

main_test.go

• TestMergeConfigs_Rules/Protect/Passthrough/Template
• TestFetchExtendsConfig — valid fetch, 404, invalid JSON, nested extends not followed
• TestReadLocalConfig — valid file, missing file, invalid JSON
• TestLoadExtendsConfig — http dispatches to fetch, local path dispatches to read
• TestProcessMessage_WithExtends — end-to-end with merged config

Merge strategy

Field	Strategy
rules	base is default; local key wins on conflict
protect	union (base ∪ local), deduped
passthrough	union (base ∪ local), deduped
template	local wins; fall back to base
extends	base config's own extends is ignored (no recursive loading)

[npayfebot]

✅ Changeset detected

Latest commit: 79f0831

@naverpay/commithelper-go package have detected changes.

If no version change is needed, please add skip-detect-change to the label.

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 5 packages

Name	Type
@naverpay/commithelper-go	✨ Minor
@naverpay/commithelper-go-darwin-arm64	✨ Minor
@naverpay/commithelper-go-darwin-x64	✨ Minor
@naverpay/commithelper-go-linux-x64	✨ Minor
@naverpay/commithelper-go-win32-x64	✨ Minor

_{powered by: naverpay changeset detect-add actions}

[kyungmi]

/canary-publish

[npayfebot]

Published Canary Packages

@naverpay/commithelper-go@1.5.0-canary.260703-d9e0a03
@naverpay/commithelper-go-darwin-arm64@1.5.0-canary.260703-d9e0a03
@naverpay/commithelper-go-darwin-x64@1.5.0-canary.260703-d9e0a03
@naverpay/commithelper-go-linux-x64@1.5.0-canary.260703-d9e0a03
@naverpay/commithelper-go-win32-x64@1.5.0-canary.260703-d9e0a03

[kyungmi]

/canary-publish

[npayfebot]

Published Canary Packages

@naverpay/commithelper-go@1.5.0-canary.260703-79f0831
@naverpay/commithelper-go-darwin-arm64@1.5.0-canary.260703-79f0831
@naverpay/commithelper-go-darwin-x64@1.5.0-canary.260703-79f0831
@naverpay/commithelper-go-linux-x64@1.5.0-canary.260703-79f0831
@naverpay/commithelper-go-win32-x64@1.5.0-canary.260703-79f0831

[arale-dev]

작업 감사합니다!

[djk01281]

감사합니다 !!