chore: prepare v1.0.0 release

[bombillazo]

Summary

• Bump version from 0.6.1 to 1.0.0
• Update CHANGELOG with v1.0.0 release notes including observability features and security audit
• Replace pre-release warning with stable version note in README

Changes

package.json

• Version updated to 1.0.0

CHANGELOG.md

• Added v1.0.0 section with:
  • Observability module features (fingerprinting, structured logging, OpenTelemetry)
  • Framework integration examples
  • Security audit notes
  • API stability commitment

README.md

• Replaced pre-v1.0 warning with semantic versioning commitment note

Test plan

• All 326 tests passing
• Build succeeds
• Lint passes
• npm publish dry-run successful

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (c936f4f) to head (0cb8345).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main       #25   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            9         9           
  Lines         1160      1160           
  Branches       201       250   +49     
=========================================
  Hits          1160      1160           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.