Upgrade build tooling and migrate frontend assets to Gradle

[ruibaby]

Move frontend asset generation into the Gradle resource lifecycle and align the project with the current Halo plugin scaffold.

• Upgrade to Halo 2.26, Java 21, Gradle 9.4, and DevTools 0.8.
• Make packages both a Gradle subproject and the pnpm workspace root, using pnpm 12.
• Build frontend assets into package-local output directories and copy them into the plugin through processResources.
• Track workspace dependency manifests for installation, support incremental builds, and clean stale generated resources.
• Update frontend dependencies, Git hooks, development documentation, and CI/CD actions.

The npm library remains ESM, and the theme bundle retains SearchWidget.open() and its existing asset URLs.

Compatibility

The minimum supported Halo version increases from 2.17 to 2.26. Upgrade Halo before installing this plugin version.

Validation

Passed with the final pnpm 12.10.1 configuration:

• pnpm -C packages install --frozen-lockfile
• ./gradlew clean build with Java 21
• pnpm -C packages check
• pnpm -C packages/search-widget exec tsc --noEmit -p tsconfig.test.json
• pnpm -C packages test — all 11 browser tests passed
• git diff --check

Additional checks performed during the migration covered incremental frontend builds, a Chromium smoke test of the production IIFE bundle, JAR asset contents, stale resource cleanup, exclusion of legacy source-directory assets, frozen-lockfile rejection after changing a workspace dependency manifest, and an npm package dry run.

A full Halo runtime test and remote GitHub Actions execution have not been performed. The build retains an upstream DevTools Gradle deprecation warning.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-08T09:29:51.649174Z	c28513b	PR opened

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