refactor: reduce parameter count of bandwidthChecker.windowMetricLabels

[joshiste]

Summary

Follow-up to #181, which itself was a follow-up to #180. SonarCloud flagged windowMetricLabels (introduced in #181) at 9 parameters against the 7 allowed - #181 merged before this could be folded in, so it's a separate small PR. Bundles the parameters into a windowSnapshot struct; no behavior change.

Test plan

• go test ./exthttpcheck/... (including -race) passes
• go build, go vet, gofmt -l clean

[claude]

Claude finished @joshiste's task in 1m 2s —— View job

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Claude finished @unknown's task

Tasks:

• Check for previously unresolved Claude review threads and see if they were addressed (none exist — this is a fresh PR)
• Gather context on the PR changes
• Review new changes for bugs, security, performance, concurrency issues

Review

This is a clean, mechanical refactor exactly as described: windowMetricLabels now takes a single windowSnapshot struct instead of 9 positional parameters, addressing the SonarCloud cognitive-complexity/parameter-count flag left over from #181. I compared the diff against origin/main and traced every field through emitWindowMetric → windowSnapshot → windowMetricLabels.

• All 9 fields are wired through correctly with no transposition errors (each struct field maps to the same value/label it replaced).
• No behavior change: label keys, formatting (strconv.FormatInt/FormatBool/FormatFloat), and the statusCounts/transportErrors aggregation logic are untouched.
• No new concurrency exposure — windowSnapshot is passed by value into a still-synchronous call path; no shared/mutable state is introduced.
• No security or performance concerns; this is a pure signature/struct restructuring.

One very minor style nit (not flagging as an issue per review scope): statusCounts := w.statusCounts / transportErrors := w.transportErrors (lines 393–394) are just aliases and could reference w.statusCounts/w.transportErrors directly, but this is a non-behavioral readability preference, not a defect.

Note: I was unable to run go build, go vet, or gofmt -l in this sandbox (tool permission prompts aren't approvable in this automated context), but the PR description states these were already run and passed, and the diff itself is straightforward enough to review statically with confidence.

No bugs, security issues, or concurrency problems found. Looks good to merge.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud