chore: merge unstable into epbs (CI check only, do not squash)

[shane-moore]

DO NOT MERGE / DO NOT SQUASH. This PR runs CI for a true merge of unstable into epbs. After CI passes, its tested merge commit will be pushed directly to epbs, preserving both parents and the incoming commits' ancestry. Please leave the do-not-merge label in place.

Brings in #1339 (gossipsub control-message limit), #1340 (committee post-consensus send-once), and #1341 (slow-peer penalty decay).

The only textual conflict was adjacent method additions in the signature collector. The resolution retains ePBS proposer-packet signing and registered-signature waiting alongside the new committee batch helper. Local-share injection remains in place when repeat committee broadcasts are suppressed or sender admission fails. The collector tests merged without changes; dependency pins remain unchanged.

Validation: both overlapping files reviewed against both parents, with no dropped methods or duplicate fields; workspace all-targets check, formatting, and lint passed. Release-mode tests passed: all 51 signature-collector tests and all 7 peer-scoring tests, including the queue-full slow-peer regression.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 97.34513% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.99%. Comparing base (6817d74) to head (985c33a).
⚠️ Report is 1 commits behind head on epbs.

Files with missing lines	Patch %	Lines
anchor/network/src/scoring/peer_score_config.rs	97.10%	2 Missing ⚠️
anchor/signature_collector/src/lib.rs	97.61%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             epbs    #1342      +/-   ##
==========================================
+ Coverage   80.88%   80.99%   +0.10%     
==========================================
  Files         179      179              
  Lines       41247    41339      +92     
==========================================
+ Hits        33364    33483     +119     
+ Misses       7883     7856      -27     

Flag	Coverage Δ
rust	80.99% <97.34%> (+0.10%)	⬆️

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