protect yurthub transport client map from races

[shiavm006]

• Add sync.RWMutex to transportAndClientManager and fakeTransportManager to guard access to serverToClientset.
• Build serverToClientset maps completely before publishing them on the manager structs to avoid concurrent writes.
• Change ListDirectClientset in both managers to return a shallow copy of the internal map, preventing external callers from mutating internal state.
• Keep the existing Interface API unchanged while ensuring safe concurrent reads and better encapsulation.

[codecov]

Codecov Report

❌ Patch coverage is 77.27273% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 44.25%. Comparing base (3381599) to head (29cc9f5).
⚠️ Report is 15 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/yurthub/transport/transport.go	60.00%	10 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2510      +/-   ##
==========================================
+ Coverage   44.12%   44.25%   +0.12%     
==========================================
  Files         399      399              
  Lines       26564    26590      +26     
==========================================
+ Hits        11722    11768      +46     
+ Misses      13779    13758      -21     
- Partials     1063     1064       +1     

Flag	Coverage Δ
unittests	44.25% <77.27%> (+0.12%)	⬆️

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[shiavm006]

@rambohe-ch @zyjhtangtang there coverage is 0% because there are no tests for the transport package should i add one for it ?
like little bit confused as no prexisting one for this package

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[shiavm006]

@rambohe-ch any thoughts ?

[shiavm006]

@zyjhtangtang would u like to look in to it

[shiavm006]

@zyjhtangtang could u look into this

[shiavm006]

@zyjhtangtang any thoughts on this

[shiavm006]

@zyjhtangtang ??

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.