Bug: OpencodeSSRPlugin with empty directory from ServerStatus breaks store lookups

[drewsephski]

Bug

The ServerStatus component in apps/web/src/app/server-status.tsx renders an OpencodeSSRPlugin with directory: "":

<OpencodeSSRPlugin
    config={{
        baseUrl: "/api/opencode",
        directory: "", // No specific directory for global operations
    }}
/>

This sets window.__OPENCODE = { baseUrl: "/api/opencode", directory: "" }. When the user navigates to a session page, if the URL doesn't include ?dir= or the session page's own OpencodeSSRPlugin doesn't render (guarded by {directory && ...}), the config retains directory: "".

Impact

All hooks that look up store data by cfg.directory (like useMessages, useMessagesWithParts) query state.directories[""], but SSE events store data under the real directory path (e.g., "/Users/user/project"). This causes:

1. Initial messages don't hydrate — hydrateMessages stores under the real directory, hooks look under ""
2. New messages never appear — SSE updates go to one store key, UI reads from another
3. No x-opencode-directory header sent — empty string is falsy, so createOpencodeClient skips setting the header

Additional: directory is required in OpencodeConfig

OpencodeConfig requires directory: string (non-optional), making it impossible to render the plugin without a directory. It should be optional so the session page can override the ServerStatus default even when the directory isn't available from the URL.

Fix

1. Make directory optional in OpencodeConfig
2. Always render OpencodeSSRPlugin in the session layout to override ServerStatus
3. Pass directory: directory ?? "" to maintain a consistent lookup key

Logs

[useSendMessage] config: {baseUrl: '/api/opencode', directory: ''}
[useSSEEvents] Received event for /Users/drewsepeczi/opencode-vibe : session.status
// Two different keys — data never matches