fix(claude): retain native UUID separately from Go lane digest

Author: lidge-jun

devlog/_plan/260912_cache_lane/025_affinity_native.md

@@ -13,3 +13,5 @@ MODIFY tests/providers/opencode-go-session-header.test.ts: real handler random/f
 MODIFY structure/data-planes/inbound-compat.md final affinity contract to describe private native lane at final canonical destination; mapped links already exist. Preserve source authors. C source audit + diff check, then exact final-tip hosted run tracked in verification cycle. D records missed earlier review scenario and repair head.
 
 Test placement amendment: NEW tests/claude-integration/claude-native-affinity.test.ts and both layout mappings instead of enlarging the existing 600-line Go suite. Same real-handler matrix plus policy wrapper with real core and controlled trace.
+
+C review correction: normalizeLogConversationId hashes its input, so native projection retains raw validated UUID separately; only metadataGoLane uses normalized hash. Preserve fixed historical UUID oracle, no cache-identity migration.

src/server/claude-messages.ts

@@ -869,12 +869,13 @@ async function handleClaudeMessagesWithBudget(
   }
   // Carry Go identity out of band: a combo's preflight target may differ from its
   // actual dispatch/fallback target. Never add Go-only identity to replay headers.
-  const metadataGoLane = cacheKeySource === "metadata"
+  const claudeNativeSessionId = cacheKeySource === "metadata"
     && typeof internalBody.prompt_cache_key === "string"
     && isRec(anthropicBody)
     && conversationIdFromClaudeMetadata(isRec(anthropicBody.metadata) ? anthropicBody.metadata : undefined) !== undefined
-    ? normalizeLogConversationId(uuidFromHex(internalBody.prompt_cache_key))
+    ? uuidFromHex(internalBody.prompt_cache_key)
     : undefined;
+  const metadataGoLane = normalizeLogConversationId(claudeNativeSessionId);
   // Without any valid conversation identity, fall back to the request-scoped lane
   // allocated on the admitted client request (#4172): stable across retries and
   // route reconstruction, distinct per request, and never derived from a shared
@@ -927,7 +928,7 @@ async function handleClaudeMessagesWithBudget(
     // would fire, disagreeing with the pre-flight decision above.
     inboundWire: "anthropic",
     claudeGoAffinity: { sessionLane: claudeGoSessionLane },
-    claudeNativeSessionId: metadataGoLane,
+    claudeNativeSessionId,
     stripClaudeMainAuthForNoncanonicalForward: true,
     ...(trustedClaudeMainAuth ? { trustedClaudeMainAuth } : {}),
     // Claude's internal stored-main enrichment is not an original caller credential.