fix: proxy direct APNs HTTP2 sessions (#74905)

Summary:
- This PR routes direct APNs HTTP/2 sends through an APNs allowlisted managed-proxy CONNECT wrapper, adds APNs proxy validation/docs/guardrails, and expands regression and live-test coverage.
- Reproducibility: yes. source-reproducible: current main `sendApnsRequest()` still uses raw `http2.connect(au ... nly covers HTTP/global-agent/Undici hooks. I did not run a live APNs reproduction in this read-only review.

Automerge notes:
- PR branch already contained follow-up commit before automerge: test: guard raw HTTP2 APNs connections
- PR branch already contained follow-up commit before automerge: test: guard raw HTTP2 with OpenGrep
- PR branch already contained follow-up commit before automerge: lint: ban raw HTTP2 imports
- PR branch already contained follow-up commit before automerge: fix: use managed proxy state for APNs
- PR branch already contained follow-up commit before automerge: test: exercise APNs active proxy state
- PR branch already contained follow-up commit before automerge: fix: reject conflicting managed proxy activation

Validation:
- ClawSweeper review passed for head dab7c86a75.
- Required merge gates passed before the squash merge.

Prepared head SHA: dab7c86a75
Review: https://github.com/openclaw/openclaw/pull/74905#issuecomment-4350181159

Co-authored-by: jesse-merhi <79823012+jesse-merhi@users.noreply.github.com>
Co-authored-by: clawsweeper <274271284+clawsweeper[bot]@users.noreply.github.com>

test/scripts/test-live-shard.test.ts

@@ -74,6 +74,9 @@ describe("scripts/test-live-shard", () => {
     expect(selectLiveShardFiles("native-live-src-gateway-core", allFiles)).not.toEqual(
       expect.arrayContaining(["src/gateway/gateway-cli-backend.live.test.ts"]),
     );
+    expect(selectLiveShardFiles("native-live-src-infra", allFiles)).toEqual(
+      expect.arrayContaining(["src/infra/push-apns-http2.live.test.ts"]),
+    );
     expect(selectLiveShardFiles("native-live-test", allFiles)).toEqual(
       expect.arrayContaining([
         "test/image-generation.infer-cli.live.test.ts",