refactor: consolidate PNG encoder and safeParseJson utilities (#12457)

- Create shared PNG encoder module (src/media/png-encode.ts)

- Refactor qr-image.ts and live-image-probe.ts to use shared encoder

- Add safeParseJson to utils.ts and plugin-sdk exports

- Update msteams and pairing-store to use centralized safeParseJson

extensions/msteams/src/store-fs.ts

@@ -1,6 +1,7 @@
 import crypto from "node:crypto";
 import fs from "node:fs";
 import path from "node:path";
+import { safeParseJson } from "openclaw/plugin-sdk";
 import lockfile from "proper-lockfile";
 
 const STORE_LOCK_OPTIONS = {
@@ -14,14 +15,6 @@ const STORE_LOCK_OPTIONS = {
   stale: 30_000,
 } as const;
 
-function safeParseJson<T>(raw: string): T | null {
-  try {
-    return JSON.parse(raw) as T;
-  } catch {
-    return null;
-  }
-}
-
 export async function readJsonFile<T>(
   filePath: string,
   fallback: T,