feat: add stacked useTitle hook and dashboard quick refresh

[Raven062]

Summary

Adds a reusable stacked useTitle hook for nested page/section titles and wires the dashboard header refresh affordance into the live dashboard surface.

Changes

• Introduces useTitle(title, { depth }) to compose document.title from depth-ordered page/section entries.
• Keeps the public API backwards-compatible and documents the hook in docs/HOOKS.md.
• Adds regression coverage for the hook behavior in tests/unit/hooks/useTitle.test.tsx.
• Wires the dashboard header to render the new title stack and adds the quick refresh button to the dashboard header area.
• Documents component testing conventions in docs/COMPONENT_TESTING.md and links it from the top-level docs.

Notes

• Closes Add a useTitle hook that stacks page + section title #1129
• Closes Add a docs/COMPONENT_TESTING.md guide #1131
• Closes Add a "quick refresh" button on the dashboard header #1135