fix: share plugin runtime helpers

Consolidate shared plugin runtime MIME/schema helpers, preserve canonical runtime behavior, and guard QQBot STT fetches.

src/plugins/schema-validator.test.ts

@@ -146,6 +146,36 @@ describe("schema validator", () => {
     expectValidationIssue(result, "<root>");
   });
 
+  it("can isolate caller schemas that reuse the same $id with different shapes", () => {
+    const first = validateJsonSchemaValue({
+      cacheKey: "schema-validator.test.same-id.uncached",
+      schema: {
+        $id: "https://example.test/shared-schema",
+        type: "object",
+        properties: { foo: { type: "string" } },
+        required: ["foo"],
+        additionalProperties: false,
+      },
+      value: { foo: "ok" },
+      cache: false,
+    });
+    expect(first.ok).toBe(true);
+
+    const second = validateJsonSchemaValue({
+      cacheKey: "schema-validator.test.same-id.uncached",
+      schema: {
+        $id: "https://example.test/shared-schema",
+        type: "object",
+        properties: { bar: { type: "number" } },
+        required: ["bar"],
+        additionalProperties: false,
+      },
+      value: { bar: 1 },
+      cache: false,
+    });
+    expect(second.ok).toBe(true);
+  });
+
   it.each([
     {
       title: "includes allowed values in enum validation errors",

src/plugins/schema-validator.ts

@@ -20,11 +20,7 @@ type AjvLike = {
 };
 const ajvSingletons = new Map<"default" | "defaults", AjvLike>();
 
-function getAjv(mode: "default" | "defaults"): AjvLike {
-  const cached = ajvSingletons.get(mode);
-  if (cached) {
-    return cached;
-  }
+function createAjv(mode: "default" | "defaults"): AjvLike {
   const ajvModule = require("ajv") as { default?: new (opts?: object) => AjvLike };
   const AjvCtor =
     typeof ajvModule.default === "function"
@@ -44,6 +40,15 @@ function getAjv(mode: "default" | "defaults"): AjvLike {
       return URL.canParse(value);
     },
   });
+  return instance;
+}
+
+function getAjv(mode: "default" | "defaults"): AjvLike {
+  const cached = ajvSingletons.get(mode);
+  if (cached) {
+    return cached;
+  }
+  const instance = createAjv(mode);
   ajvSingletons.set(mode, instance);
   return instance;
 }
@@ -197,7 +202,24 @@ export function validateJsonSchemaValue(params: {
   cacheKey: string;
   value: unknown;
   applyDefaults?: boolean;
+  cache?: boolean;
 }): { ok: true; value: unknown } | { ok: false; errors: JsonSchemaValidationError[] } {
+  const useCache = params.cache !== false;
+  if (!useCache) {
+    const validate = createAjv(params.applyDefaults ? "defaults" : "default").compile(
+      params.schema,
+    );
+    const value =
+      params.applyDefaults && schemaHasDefaults(params.schema)
+        ? cloneValidationValue(params.value)
+        : params.value;
+    const ok = validate(value);
+    if (ok) {
+      return { ok: true, value };
+    }
+    return { ok: false, errors: formatAjvErrors(validate.errors) };
+  }
+
   const cacheKey = params.applyDefaults ? `${params.cacheKey}::defaults` : params.cacheKey;
   let cached = schemaCache.get(cacheKey);
   const schemaFingerprint =