fix: benchmark-compare port slots start at offset 1000

[pdrobnjak]

Summary

• benchmark-compare.sh slot 0 previously mapped to RUN_PORT_OFFSET=0, which uses the same default ports as standalone benchmark.sh (offset 0)
• If a stale seid from a previous standalone run is holding those ports, the baseline node in a compare run panics with bind: address already in use
• Fix: change slot-to-offset mapping from slot * 1000 to 1000 + slot * 1000, so compare runs start at offset 1000+ and never overlap with standalone benchmark default ports

Complements #2900 which added auto-claim port offsets to benchmark.sh itself.

Test plan

• Run benchmark-compare.sh — first slot should claim offset 1000, not 0
• Run standalone benchmark.sh concurrently with benchmark-compare.sh — no port collisions
• Multiple concurrent benchmark-compare.sh invocations still auto-claim non-overlapping slots

🤖 Generated with Claude Code

[github-actions]

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Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Feb 17, 2026, 3:03 PM

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 48.35%. Comparing base (4b3735f) to head (c770144).
⚠️ Report is 1 commits behind head on pd/benchmark-profiling-improvements.

❗ There is a different number of reports uploaded between BASE (4b3735f) and HEAD (c770144). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (4b3735f)	HEAD (c770144)
sei-chain	1	0

Additional details and impacted files

@@                           Coverage Diff                            @@
##           pd/benchmark-profiling-improvements    #2905       +/-   ##
========================================================================
- Coverage                                57.17%   48.35%    -8.83%     
========================================================================
  Files                                     2091      671     -1420     
  Lines                                   171173    50615   -120558     
========================================================================
- Hits                                     97872    24474    -73398     
+ Misses                                   64583    24000    -40583     
+ Partials                                  8718     2141     -6577     

Flag	Coverage Δ
sei-chain	?
sei-cosmos	48.16% <ø> (+<0.01%)	⬆️
sei-db	68.72% <ø> (ø)

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see 1543 files with indirect coverage changes

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