showcase: add showcase summary

Author: OgeonX-Ai

docs/showcase/README.md

@@ -0,0 +1,16 @@
+# Showcase
+
+This folder contains public-facing summaries and positioning notes for AI-OS.
+
+## One-line summary
+
+AI-OS turns AI-assisted coding from ad-hoc prompting into a repeatable engineering process.
+
+## Key points
+
+- SDLC state machines
+- verification-driven loops
+- prompt and context engineering
+- specialist role fan-out
+- governance and release controls
+- wiki and documentation synchronization