Final layer of polishing.

Patched a glitch that effected category creation on imported JSONs.

Category collapse/expand controls in the Manage tree

Version 1.0.4 focuses on interface cleanup and workflow fluidity while preserving the core template insertion, copying, right-click insertion, JSON import/export, local storage, and dark/light mode behavior.

The Settings page has been simplified by removing the long Import/Export explanatory paragraph and adding a ReadMe button between Import/Export and License. The ReadMe is bundled locally with the extension and links directly to the bundled GNU GPLv3 license page.

The Manage tab has been fully centered around the category tree. Categories and templates can be selected directly from the tree for editing, and new item creation now happens from contextually placed plus buttons inside the tree instead of separate top-level action buttons.

Each category now includes its own inline New Template button. When creating a template from that button, the category field is shown as a static value so the user can clearly see where the new template will be created without needing to choose from a dropdown.

A New Category button has also been moved into the tree, keeping category and template organization in one place. The plus buttons are intentionally compact so they read as part of the tree rather than as a separate control panel.

Drag-and-drop behavior has been expanded. Templates can still be dragged onto another category to move them, but they can also be reordered within a category or dropped relative to another template. Categories themselves can now be dragged and reordered in the tree as well.