plugins: add KDE Connect 0.1.0

[vampireJSV]

What is this?

KDE Connect, a bar widget: Live KDE Connect device status on the bar: connection, battery, unread notification count.

Checklist

• One folder under its catalogue with a manifest and a real preview image (not a placeholder).
• One entry added to that catalogue's registry.json (lastUpdated in YYYY-MM-DD; official: false for community items).
• Tested live in Ryoku, it renders and behaves correctly (installed with ryoku plugin add).
• tests/validate-catalogue.sh passes from the repo root.
• I own or have permission to submit this content, and it is licensed for redistribution.
• It does not overwrite user configuration or run privileged commands without clear consent.

Opened with ryoku plugin share; the product manifest and the registry entry were generated from the installed plugin.

[neur0map]

@vampireJSV please fix Registry.json

[vampireJSV]

Merged current main and resolved the plugins/registry.json conflict. Also bumped the plugin to its latest content (bar spacing fix) with the regenerated product-manifest and manifestSha256; tests/validate-catalogue.sh and tests/validate-store.py pass locally.