fix: normalize route paths with a leading slash

[firas-yangui]

Related issue or discussion

Fixes #589

Description

Normalize non-empty route patterns in PathMatcher::new by prepending a leading slash when one is omitted.

This keeps request matching, URL reversing, and Route::url() consistent while preserving the existing behavior for empty path patterns.

Type of change

• Bug fix
• New feature
• Documentation
• Refactor / cleanup
• Performance improvement
• Other (describe above)

Testing

• cargo test -p cot --all-features
• cargo test -p cot --all-features router:: --lib
• cargo clippy -p cot --lib --all-features -- -D warnings
• cargo fmt --all -- --check

The repository's full all-targets Clippy command currently reports two pre-existing assertions_on_constants errors in cot/src/db/fields/chrono_fields.rs.

Checklist

• I've read the contributing guide
• Tests pass locally (just test-all)
• Code passes clippy (just clippy)
• Code is properly formatted (cargo fmt)
• New tests added (regression test for bugs, coverage for new features)
• Documentation (both code and site) updated (if applicable)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Flag	Coverage Δ
rust	90.25% <100.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
cot/src/router.rs	92.17% <100.00%> (+0.17%)	⬆️
cot/src/router/path.rs	99.65% <100.00%> (+0.01%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[m4tx]

Hey, thanks for the contribution! I will have a look at the code soon, but in the meantime please note that #593 already fixes the Miri problems, so you don't have to worry too much about them.

[firas-yangui]

@m4tx Thanks for the heads-up and for taking the time to review my contribution! I’ll remove the Miri-related change so this PR stays focused on the routing issue. Looking forward to your feedback. 🙂