Add Sandip Mandal's SoB 2026 blog post on PayJoin for Cove Wallet

[Sandipmandal25]

Summary

• Add my Summer of Bitcoin 2026 midterm blog post
• Add author information in _config.yml
• Add the blog post at _posts/2026-06-27-summer-of-bitcoin-2026-adding-payjoin-to-cove-wallet.md
• Add supporting images under assets/images/blog_content/

The blog documents my midterm progress on implementing PayJoin support for Cove Wallet, covering the work completed so far, the technical challenges encountered, and the overall development journey.

[adi-shankara]

@Sandipmandal25 Thanks for the PayJoin write-up. Before publication, please make these changes:

• Cove is not currently in the README’s category list. New categories are allowed when they are justified and useful for future posts. If you want to introduce Cove as a reusable category, please add it to the README’s Available Categories list in this PR. Otherwise, the existing Wallets, Privacy, Development, and Stories categories already describe the post well.
• Please give the article a thorough grammar pass. Examples include “Bitcoin stuffs,” the fragments/run-ons around “Somewhere along the way…” and “Got in…,” several comma splices in the actor/review sections, and “Review I used to see as a hurdle.” See Writing Style and the Review Process.

Once those are updated, please reply here and we’ll re-review the PR.

[Sandipmandal25]

@adi-shankara i have updated the pr accordingly!

[adi-shankara]

@Sandipmandal25 Thanks for the follow-up; the category and grammar changes are in place. Before publication, please tighten two technical claims and refresh one status:

• The explanation that an analyst "can't tell who paid whom, or even how many people are involved" is too absolute. PayJoin breaks the common-input-ownership heuristic and makes analysis harder; it does not defeat every analysis method.
• "Even a compromised relay can't break your privacy" is also too absolute and conflates the OHTTP relay with the PayJoin directory. Please describe the narrower protection and threat model in BIP 77.
• The article says session persistence is "in final review," but Cove PR #809 merged on July 20. Please update that sentence or make it time-independent.

These fall under the README's Technical Accuracy requirement. Once updated, please reply here and we'll re-review.

[adi-shankara]

@Sandipmandal25 Friendly follow-up: this branch has not received a new commit since the July 27 review. It still needs the two absolute PayJoin privacy claims qualified to BIP 77's threat model, and the session-persistence status updated now that Cove #809 has merged.

Please push those changes and reply here so we can re-review it for publication.

[Sandipmandal25]

@Sandipmandal25 Friendly follow-up: this branch has not received a new commit since the July 27 review. It still needs the two absolute PayJoin privacy claims qualified to BIP 77's threat model, and the session-persistence status updated now that Cove #809 has merged.

Please push those changes and reply here so we can re-review it for publication.

thank you for the follow up i have pushed the changes in latest commit.