docs: add end-to-end demo with recorded GIF

scripts/demo.sh + scripts/demo_harness.py drive a real bottle through
four probes (pipelock allow, host-allowlist block, DLP body-scan
block, git-gate gitleaks rejection). docs/demo.tape is the VHS source
that renders docs/demo.gif, embedded at the top of the README as a
working proof of the security model the prose describes.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -8,6 +8,15 @@
 
 Run multiple Claude Code agents on your own machine, each scoped to its own secrets, skills, and egress allowlist.
 
+![pipelock and git-gate blocking exfil attempts against a live bottle](docs/demo.gif)
+
+Four probes against a real bottle, end-to-end:
+pipelock forwards a clean HTTPS GET to an allowlisted host,
+blocks a GET to a non-allowlisted host,
+blocks a POST whose body carries a credential pattern;
+git-gate rejects a push containing a leaked key.
+Run it yourself with `bash scripts/demo.sh`.
+
 ## Why "claude-bottle"?
 
 Each container is a bottle; Claude is the genie inside. The genie's