v0.2.0

Changelog

• docs: add 'Updating' section to README by @LarsLaskowski in #29
• Validate config at startup to prevent ticker panic by @LarsLaskowski in #30
• Fix/readme by @LarsLaskowski in #31
• Make fix-issue skill create a branch, commit, and open a PR by @LarsLaskowski in #33
• Clarify install.sh binary path and pre-install config customization in README by @LarsLaskowski in #32
• Use constant-time comparison for API key check by @LarsLaskowski in #34
• Restrict config file permissions to root and pimonitor group by @LarsLaskowski in #35
• Document Claude attribution policy in skill guides by @LarsLaskowski in #36
• Add light/dark theme toggle with persistence by @LarsLaskowski in #37
• Build dashboard bar and network rows without innerHTML to prevent stored XSS by @LarsLaskowski in #38
• Add security headers middleware (CSP, nosniff, frame protection) by @LarsLaskowski in #39
• Harden disk collector: exclude network filesystems, bound statfs, df-compatible used_percent by @LarsLaskowski in #40
• Persist metric history to disk (survive restarts) by @LarsLaskowski in #44

Full Changelog: v0.1.0...v0.2.0