fix(types): preserve request rule contracts (#9135)

Validated in local merge-train (devbox-vm-06-dev002) @ combined-tip (FAST gates: typecheck/complexity/cognitive/changelog/vitest — only pre-existing audit.test.ts flake). Evidence: /home/diegosouzapw/dev/proxys/OmniRoute/.claude/worktrees/merge-train-20260805-222248-suite.log

open-sse/services/payloadRules.ts

@@ -85,7 +85,7 @@ function clonePayloadRulesConfig(config: PayloadRulesConfig): PayloadRulesConfig
 
 function normalizeModelSpecs(value: unknown): PayloadRuleModelSpec[] {
   return toArray<JsonRecord>(value)
-    .map((item) => {
+    .map((item): PayloadRuleModelSpec | null => {
       const name = typeof item?.name === "string" ? item.name.trim() : "";
       const protocol = typeof item?.protocol === "string" ? item.protocol.trim() : "";
       if (!name) return null;

open-sse/services/specificityTypes.ts

@@ -30,6 +30,7 @@ export interface RuleInput {
   messages: Array<{ role?: string; content?: string | unknown }>;
   systemPrompt?: string;
   tools?: Array<{
+    type?: string;
     function?: { name: string; description?: string; parameters?: unknown };
   }>;
   model?: string;