#1694 fix: Dispatcher heading in release notes now shows its component name

Summary

• The dispatcher section of release PR bodies now gets a labeled changelog heading like the other components.

User Impact

• Before: in release PRs, the Unity package and project runner sections showed headings like Unity Package 3.0.0-beta.49 / uloop Project Runner 3.0.0-beta.47, but the dispatcher section showed only a bare 3.0.1-beta.13 with no component name (visible in #1693).
• After: the dispatcher heading reads Dispatcher 3.0.1-beta.13, consistent with the other components.

Changes

• Add the missing dispatcher entry to the release PR body clarifier's component display-name map.
• Extend the heading-clarification test with a dispatcher section.

Verification

• go test ./internal/automation/ in cli/release-automation (the new assertion fails without the fix)
• scripts/check-go-cli.sh passes (fmt, vet, lint, tests, builds)