clean up project metadata for tag retention policy after deletion

[MinerYang]

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Comprehensive Summary of your change

Issue being fixed

#21783

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 65.88%. Comparing base (c8c11b4) to head (a79e5f1).
Report is 514 commits behind head on main.

Files with missing lines	Patch %	Lines
src/server/v2.0/handler/retention.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main   #22174       +/-   ##
===========================================
+ Coverage   45.36%   65.88%   +20.51%     
===========================================
  Files         244     1072      +828     
  Lines       13333   115792   +102459     
  Branches     2719     2925      +206     
===========================================
+ Hits         6049    76289    +70240     
- Misses       6983    35279    +28296     
- Partials      301     4224     +3923     

Flag	Coverage Δ
unittests	65.88% <0.00%> (+20.51%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/server/v2.0/handler/retention.go	0.00% <0.00%> (ø)

... and 985 files with indirect coverage changes

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[Copilot]

Pull Request Overview

This PR ensures that when a retention policy is deleted, its associated retention_id entry is also removed from the project_metadata table.

• Adds a call to proMetaMgr.Delete after the retention policy is deleted.
• Cleans up retention_id metadata for the project to keep data consistent.

Comments suppressed due to low confidence (2)

src/server/v2.0/handler/retention.go:263

• The new metadata deletion logic is not covered by existing tests. Please add unit or integration tests to verify that proMetaMgr.Delete is called and that the retention_id entry is removed from project_metadata.

	// delete retention data in project_metadata

src/server/v2.0/handler/retention.go:264

• The variable p is not defined in this function, which will lead to a compile error. You need to retrieve the project reference (e.g., by fetching the retention policy with GetRetention) or replace p.Scope.Reference with a valid project ID source (such as params.ProjectID).

	if err := r.proMetaMgr.Delete(ctx, p.Scope.Reference, "retention_id"); err != nil {

[wy65701436]

lgtm