v2: duplicate plugin ID hangs the server — activation defect never opens readiness latch

Description

On v2, if two loaded plugins export the same id (e.g. an npm plugin and a local plugin, or a plugin whose id collides with an internal/SDK plugin), Plugin.activate dies with Duplicate plugin ID (packages/core/src/plugin.ts). The supervisor's reload loop catches the defect and logs failed to reload plugins, but never opens the readiness latch (packages/core/src/plugin/supervisor.ts), so every unbounded PluginSupervisor.flush caller blocks forever — session startup / opencode serve request handling hangs. Config changes retry activation, but a duplicate ID is deterministic, so the hang is permanent.

From the user's perspective this is silent: no inventory entry, no plugin.updated event, nothing in the /plugins dialog — only a single log line.

Plugins

Any two plugins exporting the same id.

OpenCode version

v2 (next), reproduced on origin/v2 @ aa8c1f6da

Steps to reproduce

1. Configure two plugins whose modules export the same id, e.g. two local files:

   export default { id: "probe.dup", effect: () => Effect.void }
   

2. Start opencode (TUI or serve).
3. Observe: server hangs on any path awaiting plugin readiness; log shows only failed to reload plugins with Duplicate plugin ID.

Screenshot and/or share link

No response

Operating System

Linux (Ubuntu), but platform-independent

Terminal

No response