feat: add localized plugin metadata and resource menus

[seakee]

Summary

This adds localization support for plugin-facing metadata across the plugin store, SDK schemas, and management/resource menu surfaces.

Background

Plugin display data currently has a single language path for names, authors, descriptions, config field descriptions, and resource menu labels. This makes plugin store listings and management UI menus hard to localize without custom frontend-side mapping.

Changes

• Add optional locale maps to plugin SDK types:
  • plugin metadata display fields
  • config field descriptions
  • management/resource route menu text
• Add plugin store locale metadata parsing and normalization.
• Preserve localized plugin metadata in generated install manifests.
• Add preferred locale resolution from:
  • locale query parameter
  • X-Locale header
  • Accept-Language
• Forward the resolved locale to plugin management/resource handlers through X-Locale.
• Localize plugin store list entries, installed plugin metadata, config fields, and resource menu labels.
• Fix resource menu launch URLs so default query parameters remain navigable while route dispatch still matches path-only resource handlers.
• Harden locale handling:
  • clone and normalize locale maps before exposing host snapshots
  • avoid shared locale map mutation from plugin-owned route definitions
  • keep plugin management request headers writable even when the original request has no headers

Compatibility

All locale fields are optional and preserve existing behavior when omitted. Existing plugin metadata and resource routes continue to work without changes.

Resource route dispatch remains path-based. Resource menu paths may include query parameters for launch URLs, but handler dispatch uses the path portion and forwards query values in the request object.

Testing

• go test ./internal/pluginhost ./internal/plugini18n ./internal/pluginstore ./internal/api/handlers/management ./sdk/pluginapi
• go test ./...
• go build -o /private/tmp/cpa-cli-proxy-api-test-output ./cmd/server

[gemini-code-assist]

Code Review

This pull request introduces comprehensive localization (i18n) support for plugins, updating the plugin store, manifests, registries, and metadata to handle localized display fields. It adds a new plugini18n package to manage locale normalization, preferred locale resolution from request headers/queries, and fallback lookups. The feedback recommends improving the localeCandidates function to progressively strip subtags from right to left, ensuring full support for standard BCP 47 progressive fallback (e.g., falling back from zh-Hant-HK to zh-Hant and then zh).

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 409e0531ea

ℹ️ About Codex in GitHub

Codex has been enabled to automatically review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".