fix(proxy): add stable usage keys and idempotent raw-response logging

Derive request ids from upstream envelope ids (Codex/OpenAI top-level
id, Gemini responseId, Claude message id with non-empty filtering)
scoped as session:{app_type}:{provider_id}:{id} for non-Claude sources;
Claude keeps bare session:{id} to preserve session-log convergence.

The logger now queries and conditionally writes under a single
connection guard: identical semantic replays return without writing or
notifying, session_log rows may be upgraded by proxy, and same-id
different-semantic responses land on a deterministic SHA-256 collision
fallback key instead of being overwritten. Fixes the random-UUID
INSERT OR REPLACE duplication behind #5496.

src-tauri/src/proxy/response_processor.rs

@@ -642,7 +642,8 @@ async fn log_usage_internal(
         model
     };
 
-    let request_id = usage.dedup_request_id();
+    let dedup_scope = (app_type != "claude").then_some((app_type, provider_id));
+    let request_id = usage.dedup_request_id(dedup_scope);
 
     log::debug!(
         "[{app_type}] 记录请求日志: id={request_id}, provider={provider_id}, model={model}, streaming={is_streaming}, status={status_code}, latency_ms={latency_ms}, first_token_ms={first_token_ms:?}, session={}, input={}, output={}, cache_read={}, cache_creation={}",