* fix(ai-insights): validate IPv4 loopback octets

* docs(changelog): note loopback validation fix

* fix(ai-insights): match backend IPv4 parsing

* test(ai-insights): cover non-canonical IPv4 loopback

* fix(settings): show widget version and label CLI path

Diagnostics now imports the plasmoid context to display installed metadata, and its command path has an accessible name and form label target. Add standalone accessibility and applet-context smoke regressions.

Documentation: update usage, development verification notes, and Unreleased. Existing CLI contracts, defaults, metadata, and TODO parity blockers are unaffected.

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Co-authored-by: Simone <185146821+Lucenx9@users.noreply.github.com>