feat(time): add parsetime

[franklinkim]

Description

Add timex.ParseDuration with extended d/w units, plus repo housekeeping (CI timeouts, dependabot, mise).

Type of Change

• 🐛 Bug fix
• ✨ New feature
• 💥 Breaking change
• 📝 Documentation
• ♻️ Refactoring
• ⚡ Performance
• ✅ Tests
• 🔧 Build/CI

Changes

• Add time/parseduration.go — ParseDuration parsing stdlib units plus d (day) and w (week)
• Add time/parseduration_test.go and goleak main_test.go entry
• Document in docs/time.md and README.md
• Add timeout-minutes: 15 to docs, release, test workflows
• Rework .github/dependabot.yml — security-grouped updates, add bun ecosystem, Europe/Berlin schedule
• Pin mise schema + minimum_release_age = "3d" in .mise.toml

Checklist

• My code adheres to the coding and style guidelines of the project.
• I have performed a self-review of my own code.
• I have commented on my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.