chore: align repo settings and CI configs with ergo-fetch/ergo #6

Summary

Bring ergo-wire repository settings and in-repo workflow/config files up to parity with the other published Ergo npm packages (ergo-fetch, ergo, ergo-router).

Acceptance Criteria

• Full .github/dependabot.yml (grouped updates, cooldowns, commit prefixes)
• .github/workflows/dependabot-auto-merge.yml
• .github/CODEOWNERS and .github/FUNDING.yml
• CI/release workflows include repository_dispatch docs-update step (token wiring tracked separately)
• Expanded .coderabbit.yaml matching sibling depth (wire-specific checks)
• GitHub repo settings match siblings: branch protection, signed commits, secret scanning, squash-only merges, delete branch on merge
• npm test passes