refactor(#190): collapse SDK sync bridge and remove synckit seam

sdk/package-lock.json

@@ -10,7 +10,6 @@
       "license": "MIT",
       "dependencies": {
         "@anthropic-ai/claude-agent-sdk": "^0.2.84",
-        "synckit": "^0.11.12",
         "ws": "8.20.1"
       },
       "bin": {
@@ -803,18 +802,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/@pkgr/core": {
-      "version": "0.2.9",
-      "resolved": "https://registry.npmjs.org/@pkgr/core/-/core-0.2.9.tgz",
-      "integrity": "sha512-QNqXyfVS2wm9hweSYD2O7F0G06uurj9kZ96TRQE5Y9hU7+tgdZwIkbAKc5Ocy1HxEY2kuDQa6cQ1WRs/O5LFKA==",
-      "license": "MIT",
-      "engines": {
-        "node": "^12.20.0 || ^14.18.0 || >=16.0.0"
-      },
-      "funding": {
-        "url": "https://opencollective.com/pkgr"
-      }
-    },
     "node_modules/@rollup/rollup-android-arm-eabi": {
       "version": "4.60.0",
       "resolved": "https://registry.npmjs.org/@rollup/rollup-android-arm-eabi/-/rollup-android-arm-eabi-4.60.0.tgz",
@@ -1707,21 +1694,6 @@
         "url": "https://github.com/sponsors/antfu"
       }
     },
-    "node_modules/synckit": {
-      "version": "0.11.12",
-      "resolved": "https://registry.npmjs.org/synckit/-/synckit-0.11.12.tgz",
-      "integrity": "sha512-Bh7QjT8/SuKUIfObSXNHNSK6WHo6J1tHCqJsuaFDP7gP0fkzSfTxI8y85JrppZ0h8l0maIgc2tfuZQ6/t3GtnQ==",
-      "license": "MIT",
-      "dependencies": {
-        "@pkgr/core": "^0.2.9"
-      },
-      "engines": {
-        "node": "^14.18.0 || >=16.0.0"
-      },
-      "funding": {
-        "url": "https://opencollective.com/synckit"
-      }
-    },
     "node_modules/tinybench": {
       "version": "2.9.0",
       "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",