fix(gravity): identify health probes

[jhaynie]

Summary

• set a distinct User-Agent on Gravity HTTP health probes
• add a regression test covering the probe User-Agent

Validation

• go test ./gravity

This lets ion distinguish hadron/gravity reconnect probes from public health checks during tableflip.

Summary by CodeRabbit

• Chores

  • Updated health probe requests to include an identifying User-Agent header for better request traceability.

• Tests

  • Added test coverage for health probe User-Agent header validation.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

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Run ID: d2459196-5d4b-4020-b47b-a4208a91cea1

📥 Commits

Reviewing files that changed from the base of the PR and between f5cf80e and 7038943.

📒 Files selected for processing (2)

• gravity/grpc_client.go
• gravity/health_probe_test.go

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📝 Walkthrough

Walkthrough

Adds a public constant GravityHealthProbeUserAgent to identify health probe HTTP requests. Updates the health probe HTTP request method to set the User-Agent header to this constant and introduces a test to verify the header is correctly set.

Changes

Health Probe User-Agent Header

Layer / File(s)	Summary
Constant Definition gravity/grpc_client.go	Introduces exported GravityHealthProbeUserAgent constant with value "Agentuity-Gravity-HealthProbe/1.0" to identify health probe requests.
Health Probe Implementation gravity/grpc_client.go	The doHealthProbe method sets the User-Agent header to the new constant before sending the HTTP request.
Test gravity/health_probe_test.go	New test TestDoHealthProbeSetsGravityUserAgent verifies that HTTP health probe requests include the correct User-Agent header value.

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