Polish workflow UX, docs, localization, and release automation

[YunaBraska]

What changed

• Adds the JUnit-style workflow run tree polish, run toolbar actions, rerun/delete/download behavior, and tighter workflow log handling.
• Expands workflow completion/highlighting/validation around syntax keys, auto-popup behavior, quick-fix icons, and left-ruler marker boundaries.
• Hardens release automation: merging to main creates the date tag, updates pluginVersion, promotes CHANGELOG.md, builds/verifies the plugin, creates the GitHub release with changelog notes, and hands off to Marketplace publishing.
• Adds shared build setup and cache restoration for CI runs.
• Refreshes the editor test matrix and removes stale TODO/FIXME code comments.
• Localizes all top-20 resource bundles and adds tests to catch missing keys, placeholder drift, encoding damage, leaked translation tokens, and English fallback.

Why

The plugin now behaves closer to native JetBrains workflow tooling: less gutter noise, better run feedback, stronger completion boundaries, fewer untranslated UI crumbs, and a release path that starts when you merge instead of when someone performs calendar math by candlelight.

Validation

• ./gradlew test --tests com.github.yunabraska.githubworkflow.services.WorkflowQuickFixTest --no-daemon --warning-mode all
• ./gradlew --no-daemon check verifyPlugin buildPlugin --warning-mode all
• Simulated changelog promotion/extraction for v2026.5.23; release notes come from CHANGELOG.md instead of fallback text.
• GitHub PR checks passed for push and pull-request events.