update: set MaxPacketMsgPayloadSize use MB unit

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[github-actions]

The latest Buf updates on your PR. Results from workflow Buf / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Jan 21, 2026, 8:00 PM

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 44.04%. Comparing base (3889e9a) to head (4ce4b0b).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2729      +/-   ##
==========================================
+ Coverage   43.10%   44.04%   +0.94%     
==========================================
  Files        1635     1986     +351     
  Lines      128732   162970   +34238     
==========================================
+ Hits        55487    71784   +16297     
- Misses      68271    84667   +16396     
- Partials     4974     6519    +1545     

Flag	Coverage Δ
sei-chain	46.20% <ø> (+<0.01%)	⬆️
sei-cosmos	38.06% <ø> (-0.01%)	⬇️
sei-db	68.72% <ø> (-0.23%)	⬇️
sei-tendermint	47.57% <ø> (?)

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see 358 files with indirect coverage changes

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[github-actions]

Backport failed for release/v6.3, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin release/v6.3
git worktree add -d .worktree/backport-2729-to-release/v6.3 origin/release/v6.3
cd .worktree/backport-2729-to-release/v6.3
git switch --create backport-2729-to-release/v6.3
git cherry-pick -x b0d0f599fe005bb66b91c1a46432fcc57f1d5e60