fix(core): preserve location scope for plugin event subscriptions and catalog reloads - #57186

Issue for this PR

N/A

Type of change

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

What does this PR do?

Preserves Location scoping for non-internal plugins (SdkPlugins, InstancePlugins, and package/local plugins) when they subscribe to events or trigger asynchronous catalog reloads:

1. PluginHost.event.subscribe (packages/core/src/plugin/host.ts:258): Provides Stream.provideService(Location.Service, location) on bus.subscribe(), matching Rpc.client.events.subscribe (packages/core/src/rpc.ts:166). Because Plugin.load (packages/core/src/plugin.ts:68-73) strips Location.Service from the fiber context of non-internal plugins via Effect.updateContext, ctx.event.subscribe() previously saw Location.Service = Option.none() and leaked events from all booted Locations on the server.
2. Catalog State.create notify hooks (packages/core/src/agent.ts, command.ts, integration.ts, reference.ts, skill.ts, websearch.ts): Captures Effect.serviceOption(Location.Service) at layer construction time and stamps { location } on bus.publish when present, matching Provider (packages/core/src/provider.ts:482) and Model (packages/core/src/model.ts:249). Previously, when a non-internal plugin called ctx.<domain>.reload() or ctx.integration.connection.status(...) asynchronously from a fiber where Location.Service had been stripped by Plugin.load, bus.publish emitted an unlocated (location: undefined) .updated event that clients dropped at packages/client/src/solid/data.ts:1256 (if (!event.location) return).

How did you verify your code works?

cd packages/core && bun test test/plugin/supervisor.test.ts

Added scopes external plugin event subscriptions and async catalog reloads to the plugin's location in packages/core/test/plugin/supervisor.test.ts.

Checklist

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