Experiment: UI for linking external plugins and themes

[cbravobernal]

Experiment / spike — pairs with the CLI work in #3123. Branch base is add-plugin-theme-link-cli so the diff shows only the UI additions.

Goal

Fixes #1728

Mirror the CLI feature (studio plugin/theme link|unlink|list-linked) with a UI surface so non-CLI users can manage symlinks from the Studio app.

ui.mp4

Surfaces added

• New site-detail tab "Linked extensions" with two sections: Plugins, Themes
• + Link plugin / + Link theme buttons → native folder picker → validate → symlink
• Unlink per row → confirmation dialog → remove symlink only (source untouched)
• Per-row "Open in…" kebab menu (mirrors Overview's Shortcuts section): Finder / File Explorer, user's configured editor (VS Code, etc.), user's configured terminal (iTerm, Terminal, etc.) — all point at the linked source path.
• Inline error/notification feedback via existing showErrorMessageBox / showNotification.

Architecture

UI delegates entirely to the CLI via a child process — no duplicated symlink/validation logic in the main process. Mirrors the pattern established for import/export in #3129 (execute-import-command.ts / execute-export-command.ts).

• apps/studio/src/modules/cli/lib/execute-link-command.ts — thin wrapper over executeCliCommand that shells out to studio plugin|theme link|unlink|list-linked and awaits completion. Parses list-linked --format json stdout, surfaces CLI errors via CliCommandError.message.
• IPC handlers in apps/studio/src/ipc-handlers.ts (6 of them) now do nothing but resolve the site path and call the wrapper. Zero business logic in main.
• Any CLI-side hardening (path traversal, recursive-source guard, empty-basename, OWASP fixes already landed on CLI: Add plugin and theme link management. #3123) automatically applies to the UI path. No parallel-hardening drift risk.

Files

• apps/studio/src/modules/cli/lib/execute-link-command.ts — new. CLI wrapper + LinkedExtension type.
• apps/studio/src/ipc-handlers.ts — 6 handlers: linkPlugin, unlinkPlugin, listLinkedPlugins + theme equivalents. All async, take siteId, fork the CLI.
• apps/studio/src/preload.ts — exposes the 6 handlers via ipcRendererInvoke.
• apps/studio/src/stores/linked-extensions-api.ts — RTK Query slice with useGet*Query and useLink*/useUnlink*Mutation hooks; auto-invalidates list on mutation. queryFn wraps IPC calls in try/catch and returns structured { error } so .unwrap() rejects with a readable message instead of [object Object].
• apps/studio/src/stores/index.ts — registers slice in store + middleware.
• apps/studio/src/hooks/use-content-tabs.tsx — adds 'linked-extensions' tab between Previews and Import / Export.
• apps/studio/src/components/site-content-tabs.tsx — conditional render for the new tab.
• apps/studio/src/components/content-tab-linked-extensions.tsx — the tab UI itself.

Removed in the refactor: apps/studio/src/lib/plugin-theme-link.ts (231 lines) and its test file (167 lines). Net −356 lines.

Status

• Lint clean (npx eslint --fix on all touched files)
• Type check clean (npx tsc -p apps/studio/tsconfig.json --noEmit)
• All studio tests pass locally (850/850)
• CLI tests for plugin/theme still pass (51/51)
• Manual UI verification — tab + dialog + folder picker + Open-in menu (Finder/editor/terminal) + Unlink flow all exercised in dev Studio against a real site with /tmp/test-plugin and /tmp/test-theme fixtures.
• No duplicated logic between CLI and Studio main process.
• i18n strings reviewed for tone / wording
• Telemetry hooks (CLI added PluginCommandLoggerAction / ThemeCommandLoggerAction; UI side relies on CLI telemetry via child process).

What this is NOT

This is a vibe-coded spike to validate the UI shape and IPC surface. Architecture, error UX, and string copy are starting points, not merge-ready polish.