feat: rich content previews, link handling, and startup optimizations

- Render image URLs, SVGs, and base64 data URIs as thumbnails in list entries
- Show URLs with external-link-symbolic icon and blue styling
- Press Space on a URL to open it in the default browser (Gtk.show_uri_on_window)
- Add "Preview rich content" and "Open links on Space" toggles in Settings
- Fix switch slider border-radius to always be circular
- Add async remote image, SVG, and data URI loading to ImageHandler with LRU caching
- Show window immediately on startup, defer controller init to idle cycle
- Parse CSS once at startup instead of twice
- Disable file logging in non-debug mode to avoid I/O on every start
- Fix gi.require_version() call order before clipse_gui imports

Author: d7omdev

clipse_gui/__init__.py

@@ -1 +1 @@
-__version__ = "0.6.0"
+__version__ = "0.7.0"