feat(core): port v2 runtime fixes onto dev

Cherry-picks the packages/core changes from the v2 branch onto dev:
- combined ordered stdout/stderr in AppProcess + bash structured output
- edit/apply-patch return FileDiff info with status and line stats
- ignore no-op model switches; record reasoning timestamps
- return unexpected local tool defects to the model and continue
- keep OAuth account metadata out of request bodies
- nest OpenAI reasoning effort/summary options
- load OpenCode provider config asynchronously; batch plugin boot
- export latest public event manifest

Includes the supporting schema reasoning time field and regenerated
client/SDK types.

packages/core/src/session.ts

@@ -400,7 +400,13 @@ export const layer = Layer.effect(
         })
       }),
       switchModel: Effect.fn("V2Session.switchModel")(function* (input) {
-        yield* result.get(input.sessionID)
+        const session = yield* result.get(input.sessionID)
+        if (
+          session.model?.providerID === input.model.providerID &&
+          session.model.id === input.model.id &&
+          (session.model.variant ?? "default") === (input.model.variant ?? "default")
+        )
+          return
         yield* events.publish(SessionEvent.ModelSwitched, {
           sessionID: input.sessionID,
           messageID: SessionMessage.ID.create(),