docs(readme): make the repo-positioning paragraph benefit-led

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0145qhfty9sRLm3HUvNBFxpk

Author: claude

README.md

@@ -16,11 +16,12 @@
 
 `Fits in an agent's context` · `Typed, validated, governed` · `Self-host anywhere` · Apache-2.0
 
-**This repository is the open-source framework** — the protocol
-(`@objectstack/spec`), microkernel, SDK, CLI, and production runtime,
-Apache-2.0 end to end. Prefer the platform operated for you? That's
+**Everything in this repo is the open stack** — protocol, microkernel, SDK,
+CLI, and the production runtime, Apache-2.0 with no open-core asterisks. You
+can build, ship, and self-host real apps from here alone. Rather have the
+platform run for you, AI Builder and governance included? That's
 **[ObjectOS](https://github.com/objectstack-ai/objectos)**, the commercial
-runtime environment built on it.
+runtime environment built on this stack.
 
 <p align="center">
   <img src="docs/screenshots/architecture.png" width="940" alt="ObjectStack architecture: author typed Zod metadata (objects, flows, views, policies); the microkernel compiles it into a versioned JSON artifact and loads plugins, drivers, and services; it generates a REST API, client SDK, Console and Studio UI, and MCP tools used by developers and AI agents, governed by Auth, RBAC, RLS, FLS, and audit, over PostgreSQL, MySQL, SQLite, or MongoDB">