Refine section spacing and restore simple debug clear action

[Lyptik]

Summary

Small sidebar spacing pass:

• add a little breathing room directly below each open section header
• reduce the bottom padding of section content, which especially tightens the space below Advanced rows
• remove the remaining bottom padding inside opened Advanced content
• move debug clearing back out of Advanced
• rename Clear debug data to Clear data
• render Clear data as a lightweight text/link-style action above the debug inspector

The obsolete Debug Advanced disclosure/state was removed from HTML and persistence because it no longer contains any settings.

No tracking, connection, rendering, or debug-processing behavior changes.