paper.md's merged-PR/contributor counts must be re-verified against the repo at JOSS submission time

[shivamlalakiya]

What's wrong

paper.md's Research impact statement (grep -n "merged pull requests" paper.md)
currently says "eleven merged pull requests from four contributors external to
the project." That matches CONTRIBUTORS.md as it stands today, but not the
actual GitHub PR history: @shubhrai23 merged three more PRs (#64, #65, #66)
and isn't in CONTRIBUTORS.md yet (see the linked credit-gap issue), and
additional PRs have merged since this sentence was written.

Whatever numbers ship in the paper need to match the repo's actual state at
the moment of JOSS submission, not the moment the sentence was drafted. A
reviewer is explicitly instructed to install and inspect the repository, and a
stale count in the one section JOSS scrutinizes hardest for honesty is a bad
place to be caught being off by two.

What to change

Before submitting, re-run and update in the same commit:

# merged PRs from accounts other than the maintainer
gh pr list -R PhilanthroPy-Project/PhilanthroPy --state merged --json author \
  --jq '[.[] | select(.author.login != "shivamlalakiya") | .author.login] | unique'

Update paper.md's Research impact statement to whatever this actually
returns at submission time, and confirm CONTRIBUTORS.md lists everyone in
that output (see the @shubhrai23 credit-gap issue).

This is a pre-submission checklist item for #83, not independent code work;
resolve it as part of closing that gate, not before.

[slegarraga]

Checked against current main before picking this up, and the stale sentence appears to already be gone: paper.md no longer contains any "merged pull requests" claim — the Research impact section was reworked when the duplicate JOSS paper was collapsed in #76, and the Acknowledgements now read simply:

We thank the PhilanthroPy contributors credited in CONTRIBUTORS.md.

So there is nothing left to recount here; the count-free phrasing delegates accuracy to CONTRIBUTORS.md permanently. Two follow-ups that keep that delegation true:

1. The credit backfill for @shubhrai23 is up as docs: credit @shubhrai23 in CONTRIBUTORS.md for #64, #65, #66 #119 (without it, the CONTRIBUTORS.md file this sentence points at under-credits by three merges).
2. If a numeric impact statement returns to the paper before submission, it should be regenerated from git log at the submission freeze rather than hand-written — happy to script that if useful.

Suggesting closure as already-fixed-by-#76, but happy to reopen the counting work if you want numbers back in the paper.