feat: manage project webhook endpoints

[phucnguyen1707]

Summary

• add project-scoped pause, resume, and delete operations for outbound webhook endpoints
• keep signing secrets and event subscriptions intact while an endpoint is paused
• remove an endpoint's delivery history when it is deleted
• expose the controls and current endpoint state in the project dashboard

Tests

• npx bun test tests/project-webhook-management.test.mjs — 3 passed
• 142 assertions passed under Bun across the non-socket, DNS policy, and DNS wire suites
• npx tsx --test tests/dns-catchall.test.mjs — 8 passed
• npx tsx --test tests/dns-server.test.mjs — 15 passed
• npx bun x tsc --noEmit
• npx bun run build

bun run test on Windows keeps the process open in the two existing socket-based DNS files above; the same timeout reproduces on an untouched upstream worktree. Their 23 assertions pass under Node with the TSX loader. The configured next lint command also prompts for a missing ESLint configuration on untouched upstream.