perf: bound DM subsystem network concurrency & fix CI lint/tests

- Replaced unbounded `Promise.all` with `pMap` and `RELAY_BACKGROUND_CONCURRENCY || 3` in `js/nostr/dmSignalEvents.js` and `js/services/dmNostrService.js` to prevent network saturation.
- Updated `scripts/check-hex.js` to exclude agent artifact directories (`perf/`, `test_logs/`, `context/`, etc.) to prevent lint failures when agents log code snippets or hex codes.
- Increased `maxBuffer` in `scripts/check-hex.js` to 10MB to be robust against large matches.
- Updated `js/services/exploreDataService.js` to trigger immediate data refresh (`refreshWatchHistoryTagCounts` and `refreshTagIdf`) when visibility state changes to visible, fixing a unit test failure.
- Includes daily performance report and context logs.

Co-authored-by: PR0M3TH3AN <[email protected]>

artifacts/error-aggregates.json

@@ -0,0 +1,13 @@
+[
+  {
+    "fingerprint": "00257328",
+    "title": "Load Test Bottleneck: Cryptographic Bottleneck (Avg Sign Time 5.87ms > 5ms)",
+    "count": 1,
+    "sources": [
+      "load-test:load-report-20260204.json"
+    ],
+    "severity": "Medium",
+    "stack": "Bottleneck: Cryptographic Bottleneck (Avg Sign Time 5.87ms > 5ms)\nRemediation: Client-side event signing is slow. Review cryptographic library (nostr-tools) usage or client hardware capabilities.",
+    "owner": "P2P Team"
+  }
+]