Use inline HTML5 video player for README demo

Replace the click-through poster link with a <video> tag so the walkthrough
plays in place with native controls instead of redirecting.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: xiangtinghe616-blip

README.md

@@ -14,9 +14,9 @@ Cash reconciliation usually lives in fragile spreadsheets. This project shows ho
 
 ### ▶ Watch the 90-second demo
 
-[![Watch the cash break resolution workbench demo](frontend/design/demo/workbench-demo-poster.png)](https://github.com/xiangtinghe616-blip/cash-reconciliation-automation/blob/main/frontend/design/demo/workbench-demo-short.mp4)
+<video src="https://github.com/xiangtinghe616-blip/cash-reconciliation-automation/raw/main/frontend/design/demo/workbench-demo-short.mp4" poster="https://github.com/xiangtinghe616-blip/cash-reconciliation-automation/raw/main/frontend/design/demo/workbench-demo-poster.png" controls muted width="100%"></video>
 
-*Click the image above to play the walkthrough.* **[▶ Try the live demo](https://cash-reconciliation-automation.vercel.app)** — no setup required.
+**[▶ Try the live demo](https://cash-reconciliation-automation.vercel.app)** — no setup required.
 
 ## How it works