chore(lint): reduce warning debt across core adapters and model clients

src/models/openai.oauth.test.ts

@@ -12,7 +12,7 @@ vi.mock('../auth/openai.js', () => ({
   })),
 }));
 
-function makeSse(events: Array<{ event: string; data: any }>): string {
+function makeSse(events: Array<{ event: string; data: unknown }>): string {
   return events
     .map((e) => `event: ${e.event}\ndata: ${JSON.stringify(e.data)}\n\n`)
     .join('');
@@ -39,8 +39,12 @@ describe('OpenAIClient OAuth (Codex)', () => {
       { event: 'response.completed', data: { type: 'response.completed', response: { usage: { input_tokens: 2, output_tokens: 2 } } } },
     ]);
 
-    globalThis.fetch = vi.fn(async (_url: any, init?: any) => {
-      const parsed = JSON.parse(init.body);
+    globalThis.fetch = vi.fn(async (_url: string | URL | Request, init?: RequestInit) => {
+      const body = typeof init?.body === 'string' ? init.body : '';
+      if (!body) {
+        throw new Error('Expected JSON body');
+      }
+      const parsed = JSON.parse(body) as Record<string, unknown>;
       expect(parsed.store).toBe(false);
       expect(parsed.stream).toBe(true);
       expect(typeof parsed.instructions).toBe('string');
@@ -54,7 +58,7 @@ describe('OpenAIClient OAuth (Codex)', () => {
       });
 
       return new Response(stream, { status: 200 });
-    }) as any;
+    }) as typeof fetch;
 
     const client = new OpenAIClient({ model: 'gpt-5.3-codex', useOAuth: true });
     const resp = await client.chat({