1.8.4

v1.8.4: rename plugin id + repo to smart-related-notes

The plugin id was related-notes, which is already taken by another community
plugin of the same id ("Related Notes" by mrboxtobox). Obsidian requires globally
unique plugin ids, so the directory submission was rejected with "An entry with this
ID already exists." The display name "Smart Related Notes" was never the problem.

Rename the id and the GitHub repo to smart-related-notes (display name unchanged).
Also updated to match: the runtime plugin-folder path (self-hosted wasm lookup), the
sidebar view type (avoids clashing if both plugins are installed), the release zip /
packaged folder, the package name, and the manual-install docs. Internal console log
prefixes and CSS class names are intentionally left as-is (no conflict).

Existing BRAT installs should be removed and re-added from Saiki77/smart-related-notes;
because the plugin folder changes, settings and the index rebuild fresh.