News399: add topics

Author: bitschmidty

_topics/en/payjoin.md

@@ -117,6 +117,9 @@ optech_mentions:
   - title: "BIPs #1483 merges BIP77 which proposes payjoin v2, an asynchronous serverless variant"
     url: /en/newsletters/2025/06/06/#bips-1483
 
+  - title: "Wallet fingerprinting risks for payjoin privacy"
+    url: /en/newsletters/2026/04/03/#wallet-fingerprinting-risks-for-payjoin-privacy
+
 ## Optional.  Same format as "primary_sources" above
 see_also:
   - title: BIP79

_topics/en/quantum-resistance.md

@@ -118,6 +118,12 @@ optech_mentions:
   - title: "Discussion of the limits of cryptographic algorithm agility in Bitcoin"
     url: /en/newsletters/2026/03/06/#the-limitations-of-cryptographic-agility-in-bitcoin
 
+  - title: "Compact Isogeny PQC can replace HD wallets, key-tweaking, silent payments"
+    url: /en/newsletters/2026/04/03/#compact-isogeny-pqc-can-replace-hd-wallets-key-tweaking-silent-payments
+
+  - title: "SHRIMPS: 2.5 KB post-quantum signatures across multiple stateful devices"
+    url: /en/newsletters/2026/04/03/#shrimps-2-5-kb-post-quantum-signatures-across-multiple-stateful-devices
+
 ## Optional.  Same format as "primary_sources" above
 see_also:
   - title: Taproot