Add pagination metrics for known tests fetch

[calvinbayer]

What does this PR do?

Adds three new distribution metrics to track known tests (Early Flake Detection) pagination behavior:

• civisibility.known_tests.pages_fetched - Number of pages fetched during pagination
• civisibility.known_tests.total_fetch_ms - Wall-clock time from first to last page request
• civisibility.known_tests.total_request_ms - Sum of individual per-page request durations

Motivation

Currently, only per-request timing is tracked. These new metrics provide observability into:

• How often pagination occurs (single vs multi-page responses)
• Backend pagination performance (total wall-clock time)
• Network overhead vs local processing time (total_fetch_ms vs total_request_ms)

Implementation Details

• Metrics are emitted only on successful completion after all pages are fetched
• If fetch fails midway (network error, invalid response), metrics are not emitted
• Per-request metrics remain unchanged (backward compatible)
• Added enum entries to CiVisibilityDistributionMetric
• Updated ConfigurationApiImpl.getKnownTestsByModule() to track timing

Testing

• Tests pass
• Code formatted with spotless

Checklist

• Tests passing
• Code formatted (spotless)
• Backward compatible (no breaking changes)
• Follows existing telemetry patterns

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	13.96 s	13.94 s	[-0.6%; +0.9%] (no difference)
startup:insecure-bank:tracing:Agent	12.90 s	13.02 s	[-1.6%; -0.3%] (maybe better)
startup:petclinic:appsec:Agent	16.80 s	16.75 s	[-0.6%; +1.2%] (no difference)
startup:petclinic:iast:Agent	16.92 s	16.42 s	[-1.5%; +7.6%] (no difference)
startup:petclinic:profiling:Agent	16.71 s	16.80 s	[-1.9%; +0.8%] (no difference)
startup:petclinic:sca:Agent	16.92 s	16.67 s	[+0.7%; +2.3%] (maybe worse)
startup:petclinic:tracing:Agent	16.05 s	16.00 s	[-0.7%; +1.5%] (no difference)

Commit: e5964e9d · CI Pipeline · Benchmarking Platform UI

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