search-with-proof: split compressed verifier archives, isolated pip installs, verifier module paths

Archives are gzipped and uploaded in parts of at most 90 MB with per-part
digests (edge request limit); pip installs ignore the task venv so transitive
dependencies land in products; the verifier sets NODE_PATH and the Java
classpath from products when starting the app.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

benchmarks/search/pilot_run.py

@@ -146,6 +146,8 @@ class Pilot:
                 stdout=diagnostic(getattr(command, "stdout", ""), maximum=1500, private=private),
                 ready_seconds=getattr(command, "ready_seconds", 0),
             )
+        if (phase == "verify" or phase.startswith("verify/")) and entry.get("stderr"):
+            entry["reason"] = entry["stderr"][-300:]
         self.record["failures"].append(entry)
 
     @contextmanager