chore: prepare v0.8.0 release metadata

[Helweg]

Summary

Prepare the v0.8.0 release branch by cutting the Apex release notes into the changelog, bumping package metadata to 0.8.0, and aligning contributor/support docs with the current protected-branch release workflow.

Changes

• bump package.json and package-lock.json from 0.7.0 to 0.8.0
• cut the existing Apex semantic parsing and Apex call-graph entries into CHANGELOG.md as ## [0.8.0] - 2026-05-14 and advance compare links
• update AGENTS.md and SECURITY.md so release guidance, language/support coverage, and protected-branch workflow match the current repo state

Testing

How were these changes tested?

• Unit tests added/updated
• Manual testing performed
• Build passes (npm run build)
• Typecheck passes (npm run typecheck)
• Tests pass (npm run test:run)
• Lint passes (npm run lint)

Release Labels

• Added at least one release category label (feature, bug, performance, documentation, dependencies, refactor, test, chore, or skip-changelog)
• Added at most one semver label (semver:major, semver:minor, semver:patch) when needed

Related Issues

• N/A (release preparation PR)