feat(tui): expose plugin manager as /plugins slash command - #47347

Issue for this PR

Closes #47345

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Adds slash names to the two plugin manager commands so the dialog is reachable by typing.

The plugin manager in packages/tui/src/feature-plugins/system/plugins.tsx already lists built-in and external plugins, toggles them with space, and installs npm plugins with local/global scope. But neither plugins.list nor plugins.install declared a slashName, and both keybinds default to none (packages/tui/src/config/keybind.ts:226-227). So the only way in was to open the palette and scroll, or configure a keybind by hand.

Every sibling dialog already has one: /mcps, /agents, /models, /skills, /themes, /status, /variants, /workspaces. Plugins were the only management dialog without.

• plugins.list -> /plugins, alias /plugin
• plugins.install -> /plugin-install

/plugins matches the existing plural convention. /plugin is the alias because that is the name Claude Code users reach for, and it is the specific ask in #23800 and #7716 (both closed into the marketplace megaissue #28696, but the UI they wanted already shipped, only the entry point was missing).

Why it works: useCommandSlashes() in packages/tui/src/keymap.tsx:260-290 builds the slash list by reading command.slashName and command.slashAliases off every reachable palette-namespace command. These two commands were already namespace: "palette", so declaring the fields is all that was needed. No new UI, no API change, no behavior change to the dialog, keybinds, or palette entries.

I checked for collisions across all slashName, slashAliases, and session-route slash: { name } values first. plugins, plugin, and plugin-install are all unused.

How did you verify your code works?

Added packages/tui/test/feature-plugins/plugins-commands.test.ts, which invokes the real plugin's tui() with a recording keymap and asserts on the registered commands (no mocking of the plugin itself).

Confirmed the test actually catches the regression: with my plugins.tsx change stashed it goes 3 fail / 0 pass, and with it restored 3 pass / 0 fail.

• cd packages/tui && bun test -> 196 pass, 1 skip, 0 fail
• cd packages/tui && bun typecheck -> clean
• cd packages/opencode && bun test test/cli/tui/plugin-toggle.test.ts test/cli/tui/plugin-install.test.ts test/config/tui.test.ts -> 38 pass, 3 skip, 0 fail
• prettier --check and oxlint clean

Also updated packages/opencode/specs/tui-plugins.md to record the slash names, and added a short "Manage plugins from the TUI" section to the plugins doc, since the manager was not documented anywhere.

Screenshots / recordings

No visual change. The dialogs are unchanged; this only adds a new way to invoke them. /plugins opens the same manager that plugins.list already opened from the palette.

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR