feat(router): support static affinity router config

[leno23]

What

• Add AffinityAware to static RouterConfig and preserve it through clone/compat conversion.
• Implement SetStaticConfig for service and application affinity routers with scope filtering.
• Add tests for static affinity routing, invalid configs, scope handling, and config cloning.

Why

Issue #3203 lists affinity static route configuration as a router follow-up. The router already supports dynamic affinity rules, but static config injection had no affinity fields or SetStaticConfig entry point.

Validation

• go test ./cluster/router/affinity ./global ./config
• go test ./cluster/router/...
• go test .
• git diff --check

Refs #3203

[codecov-commenter]

Codecov Report

❌ Patch coverage is 88.13559% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 53.67%. Comparing base (60d1c2a) to head (f04bb52).
⚠️ Report is 847 commits behind head on develop.

Files with missing lines	Patch %	Lines
cluster/router/affinity/router.go	87.03%	5 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3420      +/-   ##
===========================================
+ Coverage    46.76%   53.67%   +6.90%     
===========================================
  Files          295      493     +198     
  Lines        17172    38442   +21270     
===========================================
+ Hits          8031    20633   +12602     
- Misses        8287    16156    +7869     
- Partials       854     1653     +799     

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[Copilot]

Pull request overview

Adds support for injecting static affinity router configuration (in addition to existing dynamic config-center rules) by extending RouterConfig with AffinityAware and wiring it through clone/compat conversion and affinity router static setters.

Changes:

• Add AffinityAware to global.RouterConfig and config.RouterConfig, including clone + compat conversion support.
• Implement SetStaticConfig for service/application affinity routers with scope filtering and validation.
• Add unit tests covering static affinity routing behavior, invalid configs, scope handling, and compat/clone preservation.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
global/router_config.go	Adds AffinityAware to static router config and preserves it in Clone().
global/config_test.go	Extends router clone test to assert AffinityAware is cloned.
config/router_config.go	Adds AffinityAware to config-layer RouterConfig.
compat.go	Preserves AffinityAware when converting global router config to config router config.
compat_test.go	Adds test verifying compat conversion includes AffinityAware.
cluster/router/affinity/router.go	Adds static config injection entry points and implements affinityRoute.SetStaticConfig.
cluster/router/affinity/router_test.go	Adds tests for static affinity routing, invalid configs, and scope filtering.

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[Alanxtl]

@yangpixi @Aetherance help review this, is this pr necessary?

[Aetherance]

@yangpixi @Aetherance help review this, is this pr necessary?

@Alanxtl Previously static router config only covered the tag and condition routers. This PR adds it for the affinity router and fills a real gap. I think it's necessary.

[leno23]

Addressed the affinity static wrapper feedback in f04bb52.

What changed:

• ServiceAffinityRoute.SetStaticConfig and ApplicationAffinityRoute.SetStaticConfig now return early when the static config is same-scope but has an empty AffinityAware.Key, matching the condition/tag wrapper behavior.
• Added regression coverage to ensure such empty affinity configs do not clear an already-applied static affinity rule.

Validation:

• go test ./cluster/router/affinity passed.
• gofmt and git diff --check passed.

[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