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/package.json

@@ -104,6 +104,7 @@
     "ai-gateway-provider": "3.1.2",
     "bun-pty": "0.4.8",
     "cross-spawn": "catalog:",
+    "diff": "catalog:",
     "drizzle-orm": "catalog:",
     "effect": "catalog:",
     "fuzzysort": "3.1.0",