feat(sdk): seed host plugins before recovery and harden workerd defaults - #54219

Why

Embedded workerd consumers using @opencode/sdk/workerd/effect had to register model plugins twice (in Layer.tap and instances.configure) because EmbeddedHost.CreateOptions and OpenCodeWorkerd.CreateOptions lacked plugins and started resumeSuspendedSessions before Layer.tap ran. In addition, ModelHandler and GenerateHandler did not wait for Plugin.awaitActivation, forcing callers to poll model.list or plugin.list on cold Location boots, and the workerd profile still required manual config overrides to disable 127.0.0.1 local-provider polling, enable the portable shell scanner, and scrub host process.env keys from remote workspace shells.

What Changes

sequenceDiagram
    participant App as Embedded Consumer
    participant Host as EmbeddedHost.create
    participant Sdk as SdkPlugins.Service
    participant Handler as ModelHandler / GenerateHandler
    participant Plugin as Plugin.Service
    participant Model as Model.Service

    App->>Host: create({ plugins: [modelPlugin] })
    Host->>Sdk: register(modelPlugin)
    Host->>Host: fork resumeSuspendedSessions
    App->>Handler: model.default / generate.text (cold Location)
    Handler->>Plugin: awaitActivation (5s timeout)
    Note over Plugin,Model: modelPlugin setup calls ctx.model.list()
    Plugin->>Model: available() (direct, no self-deadlock)
    Plugin-->>Handler: ready Latch opens
    Handler->>Model: default() / generate.text()
    Handler-->>App: 200 OK

Plugin Readiness Boundary

Plugin.awaitActivation is awaited at the HTTP handler boundary (ModelHandler and GenerateHandler), never inside Model.Service or Generate.Service. During Plugin.Service.activate, PluginHost wires ctx.model.list(), ctx.model.default(), and ctx.generate.text() directly to Model.Service and Generate.Service while holding the ready Latch; keeping the wait in the HTTP handlers ensures cold HTTP/SDK requests wait for plugin registration to settle without self-deadlocking plugins that inspect models during setup(ctx) / effect(ctx).

Scope

Covers plugins seeding in @opencode/sdk, bounded Plugin.awaitActivation in ModelHandler and GenerateHandler, remote workspace shell environment isolation in Shell.create, portable shell scanner fallback when WASM assets are empty, and skipping unconfigured 127.0.0.1 local-provider discovery when no local execution plane is present.

Verification

cd packages/core && bun typecheck && bun test test/shell-parse.test.ts test/shell-retention.test.ts test/plugin/provider-ollama.test.ts
cd packages/server && bun typecheck && bun run probe:workerd && bun test test/model.test.ts test/generate.test.ts test/workerd.test.ts
cd packages/sdk && bun typecheck && bun test test/embedded.test.ts -t "generate.text|seeds|OpenCodeWorkerd"
bun run check

• packages/sdk/test/embedded.test.ts: verifies a delayed model plugin passed via OpenCode.create({ plugins: [plugin] }) and OpenCodeWorkerd.create({ plugins: [plugin] }) that calls ctx.model.list() inside its own effect(ctx) resolves on the first cold opencode.model.default and opencode.generate.text calls without polling or self-deadlock.
• packages/core/test/shell-retention.test.ts: verifies Shell.create in a workspace-backed Location (location.workspaceID !== undefined) does not inherit host process.env keys.
• packages/core/test/shell-parse.test.ts: verifies ShellParse.scan defaults to portable scanning when WASM assets are empty (parser-wasm.workerd.ts).
• packages/core/test/plugin/provider-ollama.test.ts: verifies OllamaPlugin skips unconfigured default 127.0.0.1 discovery when the Location uses EnvironmentUnavailable.spawner.

Added by the opencode bot (AI-generated).

Public API: adds plugins to OpenCode/OpenCodeWorkerd effect CreateOptions; model.list/model.default/generate.text may now return 503 ServiceUnavailableError while plugins activate (backwards compatible types, behaviour change)