docs(readme): replace stale Architecture Overview video with 3 canonical videos

Replaces the single mislabelled "Architecture Overview (2 min)"
video block (WwQXHKuZhxc) with a See AxonFlow in Action section
linking the three canonical demo videos used across the community
README and docs site:

- Community Quickstart Demo (2.5 min) — BSqU1z0xxCo
- Runtime Control Demo (3 min) — 6UatGpn7KwE
- Architecture Deep Dive (12 min) — Q2CZ1qnquhg

Brings SDK README discoverability in line with axonflow/README.md
and docs.getaxonflow.com/docs/getting-started.

Author: saurabhjain1592

README.md

@@ -24,13 +24,13 @@ This SDK is a client library for interacting with a running AxonFlow control pla
 
 A deployed AxonFlow platform (self-hosted or cloud) is required for end-to-end AI governance. SDKs alone are not sufficient—the platform and SDKs are designed to be used together.
 
-### Architecture Overview (2 min)
+### See AxonFlow in Action
 
-If you're new to AxonFlow, this short video shows how the control plane and SDKs work together in a real production setup:
+Three short videos covering different angles of the platform:
 
-[![AxonFlow Architecture Overview](https://img.youtube.com/vi/WwQXHKuZhxc/maxresdefault.jpg)](https://youtu.be/WwQXHKuZhxc)
-
-▶️ [Watch on YouTube](https://youtu.be/WwQXHKuZhxc)
+- **[Community Quickstart Demo (Code + Terminal, 2.5 min)](https://youtu.be/BSqU1z0xxCo)** — governed calls, PII block, Gateway Mode with LangChain/CrewAI, and MAP from YAML
+- **[Runtime Control Demo (Portal + Workflow, 3 min)](https://youtu.be/6UatGpn7KwE)** — approvals, retry safety, execution state, and the audit viewer
+- **[Architecture Deep Dive (12 min)](https://youtu.be/Q2CZ1qnquhg)** — how the control plane works, policy enforcement flow, and multi-agent planning
 
 ## Requirements