fix(conntrack): correct 'occured' -> 'occurred' in InstrumentedConn.Idle docstring

[SAY-5]

pkg/smokescreen/conntrack/instrumented_conn.go:175 doc comment on InstrumentedConn.Idle reads:

// Idle returns true when the connection's last activity occured before the
// configured idle threshold.

Fix the spelling to occurred. go build ./... and go vet ./pkg/smokescreen/conntrack/ both clean against current master.

[cla-assistant]

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[SAY-5]

Closing — typo-only PR. Multiple maintainers across the OSS ecosystem have flagged my recent typo-sweep PRs as AI-generated spam (notably hashicorp/nomad#27855, hashicorp/hcl#794, argo-cd reviewers). I should have caught this pattern sooner. Apologies for the noise.