test(flatkv): wait for catchup before partial-loss digest compare

[blindchaser]

The dump-flatkv tool clones a snapshot + WAL into a temp dir and only retries 3 times if a live writer rolls a new snapshot and truncates the WAL mid-clone. Running the digest comparison right after a 20s sleep while the victim is still blocksyncing reliably loses that race on busy CI runners, panicking with "source kept churning".

• increase default catchup timeout/tolerance
• print per-node heights on catchup timeout for diagnosis

Describe your changes and provide context

Testing performed to validate your change

[cursor]

PR Summary

Low Risk
Changes only an integration shell contract and timing/diagnostics; no production FlatKV or node logic is modified.

Overview
The FlatKV partial-loss integration contract now waits for the victim validator to near-sync with peers before running cross-node FlatKV digest checks.

It adds configurable CATCHUP_TIMEOUT (default 240s) and CATCHUP_TOLERANCE (default 10 blocks), plus a wait_for_catchup loop that polls seid status heights every 5s. On timeout it prints per-node heights and dumps the victim log. The digest step runs only after catch-up (or failure), avoiding flaky dump-flatkv failures when a still-blocksyncing node churns snapshots/WAL faster than the tool’s limited clone retries.

^{Reviewed by Cursor Bugbot for commit 208e601. Bugbot is set up for automated code reviews on this repo. Configure here.}

[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	May 28, 2026, 3:55 PM

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 58.21%. Comparing base (1b322f0) to head (208e601).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3516      +/-   ##
==========================================
- Coverage   59.04%   58.21%   -0.83%     
==========================================
  Files        2199     2129      -70     
  Lines      182096   173921    -8175     
==========================================
- Hits       107510   101249    -6261     
+ Misses      64935    63685    -1250     
+ Partials     9651     8987     -664     

Flag	Coverage Δ
sei-db	70.41% <ø> (ø)
sei-db-state-db	?

Flags with carried forward coverage won't be shown. Click here to find out more.
see 70 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.