fix(service-disco): apply advertExpiry cap after retry-time subtraction, not before

[tinniaru3005]

Summary

waitingTime() capped the wait at advertExpiry before registration()
subtracted the elapsed retry time (updateWaitAfterRetry()). That's the
wrong order: the cap collapses to the elapsed-time subtraction on every
retry instead of the other way around.

Fix:

• waitingTime() no longer caps by advertExpiry — it returns the raw,
  un-accumulated wait, as it must for registration() to subtract elapsed
  retry time correctly.
• registration() applies min(max(advertExpiry, ZeroDuration), tWait)
  after updateWaitAfterRetry(), right before the ticket is built. The
  max(..., ZeroDuration) also guards against a misconfigured negative
  advertExpiry producing a negative tWaitFor.

Affected Areas

• Gossipsub

• Transports

• Peer Management / Discovery

• Protocol Logic

• Build / Tooling

• Other

Compatibility & Downstream Validation

Reference PRs / branches / commits demonstrating successful integration:

• Nimbus:

• Waku:

• Codex:

Impact on Library Users

Risk Assessment

References

Additional Notes

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (fix--wait-time-cap@de85173). Learn more about missing BASE report.

Additional details and impacted files

@@                  Coverage Diff                  @@
##             fix--wait-time-cap    #2839   +/-   ##
=====================================================
  Coverage                      ?   81.23%           
=====================================================
  Files                         ?      170           
  Lines                         ?    30741           
  Branches                      ?       12           
=====================================================
  Hits                          ?    24971           
  Misses                        ?     5770           
  Partials                      ?        0           

Files with missing lines	Coverage Δ
libp2p/protocols/service_discovery/registrar.nim	67.25% <100.00%> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[SionoiS]

LGTM

Just need a clean-up. Thank you.