Fork-mode canary (re-run on 2.44.1): collapse repeated separators in s

[stackbilt-admin]

Fixes #2

Automated, sandboxed change from task 2e2e6ff1-26d4-41ea-9487-7a73278599cf. The executor retained branch and publication authority.

Harness summary:

Fixed the slugify bug and added the regression test.

Changes:

• src/slugify.ts: changed the replacement regex from /[^a-z0-9]/g to /[^a-z0-9]+/g so runs of non-alphanumeric characters collapse to a single dash.
• tests/slugify.test.ts: added the test collapses runs of separators into one dash with both required assertions.

Verification: pnpm exec vitest run tests/slugify.test.ts passed with 4 tests.

Acceptance: 6/6 checks passed (re-run by the executor, not reported by the model).

• ✅ changed_files_only — changed: src/slugify.ts, tests/slugify.test.ts
• ✅ changed_files_required — all required files changed
• ✅ max_added_lines — 6 added (limit 15)
• ✅ max_deleted_lines — 1 deleted (limit 3)
• ✅ file_contains — tests/slugify.test.ts contains "collapses runs of separators into one dash"
• ✅ tests — pnpm exec vitest run tests/slugify.test.ts: exit 0, 4 passed, 0 failed (expected 4 passed)