docs(readme): state open-source framework positioning vs ObjectOS up front

Now that the framework repo (objectstack) and the commercial product repo
(objectos) are split, make the split visible on the first screen of the
README: this repo is the Apache-2.0 framework; ObjectOS is the commercial
runtime environment, with a cross-link to its public home.

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

Author: claude

README.md

@@ -16,6 +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
+**[ObjectOS](https://github.com/objectstack-ai/objectos)**, the commercial
+runtime environment built on it.
+
 <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">
   <br><sub>One typed definition → database · REST API · client SDK · UI · MCP tools.</sub>
@@ -171,7 +177,8 @@ derived from that one source. See [ARCHITECTURE.md](./ARCHITECTURE.md).
 
 **Want it governed and hosted, with Build & Ask AI built in?**
 [ObjectOS](https://www.objectos.ai) is the commercial runtime for these
-definitions.
+definitions — [objectstack-ai/objectos](https://github.com/objectstack-ai/objectos)
+is its public home (docs, issue tracker, trademark policy).
 
 ## Ship it