Harden profiling detection and agent reports

[arkerone]

Summary

• enrich CPU, memory, and async report signals for agent-oriented analysis
• add generic CPU hotspot detection and harden detector attribution to point at user callsites
• improve agent/text/markdown reports, read-first targets, docs, skill guidance, and release changeset

Validation

• npm test
• example battery: 10/10 PASS in /tmp/lanterna-example-battery-20260515-182748/summary.json