Fix stale gRPC endpoints after app-first startup retries

[Copilot]

Description

Workflow integration tests intermittently connected to a disposed sidecar after an app-first startup retry, surfacing as transient gRPC Unavailable and Connection refused failures.

• Root cause
  • Port properties preferred the previous DaprdContainer ports over newly assigned retry overrides.
• Change
  • Explicit HTTP and gRPC overrides now take precedence over stale container mappings.
  • Startup-order coverage verifies refreshed ports remain visible after sidecar startup.

Issue reference

No linked issue.

Checklist

• Code compiles correctly
• Created/updated tests
• Extended the documentation

[codecov]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 62.62%. Comparing base (18a82b5) to head (5dd7e3f).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
src/Dapr.Testcontainers/Harnesses/BaseHarness.cs	0.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1896      +/-   ##
==========================================
- Coverage   62.64%   62.62%   -0.03%     
==========================================
  Files         338      338              
  Lines        9965     9965              
  Branches     1171     1171              
==========================================
- Hits         6243     6241       -2     
+ Misses       3401     3400       -1     
- Partials      321      324       +3     

Flag	Coverage Δ
net10.0	62.57% <0.00%> (-0.04%)	⬇️

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