[v0.1] Envoy ExtProc integration for GIE

[rootfs]

Acceptance

• ExtProc header/body mutation consistent with GIE filter chains
• Example Envoy configs for common patterns (e.g., A/B test, canary routing)

[rootfs]

@Xunzhuo is it fixed by #245 ?

[Xunzhuo]

yep

[srampal]

@Xunzhuo @rootfs I submitted a PR #229
for this on Friday which @Xunzhuo reviewed and now he has submitted a PR for the same issue after that ? That PR is on GIE and LLM-D integration using Istio as the GIE gateway.

[srampal]

/assign

[srampal]

There is an additional piece to this for Istio based GIE and that is getting addressed by PR #229