[wrossmorrow-pi-bot]

Summary

Follow-up to the example-alignment review: resolves the remaining drift for the
dedup example processor (Milestone 4 tail), while leaving the echo/digest
differences noted during the review alone.

Drift found & fixed in DedupRequestProcessor

Comparing the Java example against the Go SDK's
examples/dedup.go revealed two drifts:

1. Missing method gating. The Go dedup only applies to PUT, POST, and
   PATCH requests (dedupable). The Java version deduped regardless of method
   (as long as a digest header was present).
2. Wrong decision phase. The Java version only performed the in-flight
   check/add during the request-headers phase, but the digest is only attached
   at end-of-stream phases (request body phase for requests with bodies — the
   primary dedup use case, i.e. PUT/POST/PATCH). The Go version decides at the
   end-of-stream phases. As a result, for bodied requests the in-flight cache
   could never be populated, and the 409 duplicate path could not fire.

Fix

Rewrote DedupRequestProcessor to mirror the upstream Go semantics:

• Gate on method (PUT, POST, PATCH).
• Compute the request digest at end-of-stream phases and decide
  (cache / cancel-with-409) there.
• Add the x-extproc-request-digest header at end-of-stream.
• Clear the in-flight entry when the stream completes (response phases).

Verification

• ./gradlew clean build — BUILD SUCCESSFUL (spotless + tests).
• Smoke-tested via the LoadGen against a server running the dedup processor
  (exchanges completed without errors).

Out of scope (left as-is per your direction)

• echo example: minor path-matching (startsWith("/echo") vs regex
  /echo/.*) and response-shape differences.
• digest example: extra x-extproc-response-digest header added in Java that
  the Go example does not add.

Closes the remaining Milestone 4 example-alignment item for dedup.

[wrossmorrow]

YOLO