Feature/v2/all tools sidebar (#4151)

# Description of Changes

- Added the all tools sidebar
- Added a TextFit component that shrinks text to fit containers
- Added a TopToolIcon on the nav, that animates down to give users
feedback on what tool is selected
- Added the baseToolRegistry, to replace the old pattern of listing
tools, allowing us to clean up the ToolRegistry code
- Fixed Mantine light/dark theme race condition 
- General styling tweaks

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

frontend/src/components/tools/toolPicker/ToolPicker.css

@@ -0,0 +1,79 @@
+.tool-picker-scrollable {
+  overflow-y: auto !important;
+  overflow-x: hidden !important;
+  scrollbar-width: thin;
+  scrollbar-color: var(--mantine-color-gray-4) transparent;
+}
+
+.tool-picker-scrollable::-webkit-scrollbar {
+  width: 0.375rem;
+}
+
+.tool-picker-scrollable::-webkit-scrollbar-track {
+  background: transparent;
+}
+
+.tool-picker-scrollable::-webkit-scrollbar-thumb {
+  background-color: var(--mantine-color-gray-4);
+  border-radius: 0.1875rem;
+}
+
+.tool-picker-scrollable::-webkit-scrollbar-thumb:hover {
+  background-color: var(--mantine-color-gray-5);
+}
+
+.search-input {
+  margin: 1rem;
+}
+
+.tool-subcategory-title {
+  text-transform: uppercase;
+  padding-bottom: 0.5rem;
+  font-size: 0.75rem;
+  color: var(--tool-subcategory-text-color);
+  /* Align the text with tool labels to account for icon gutter */
+  padding-left: 1rem;
+}
+
+/* New row-style subcategory header with rule */
+.tool-subcategory-row {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+}
+
+.tool-subcategory-row-title {
+  text-transform: uppercase;
+  font-weight: 600;
+  font-size: 0.75rem;
+  color: var(--tool-subcategory-text-color);
+  white-space: nowrap;
+  overflow: visible;
+}
+
+.tool-subcategory-row-rule {
+  height: 1px;
+  background-color: var(--tool-subcategory-rule-color);
+  flex: 1 1 auto;
+}
+
+/* Compact tool buttons */
+.tool-button {
+  font-size: 0.875rem; /* default 1rem - 0.125rem? We'll apply exact -0.25rem via calc below */
+  padding-top: 0.375rem;
+  padding-bottom: 0.375rem;
+}
+
+.tool-button .mantine-Button-label {
+  font-size: .85rem;
+}
+
+.tool-button-icon {
+  font-size: 1rem;
+  line-height: 1;
+}
+
+.search-input-container {
+  margin-top: 0.5rem;
+  margin-bottom: 0.5rem;
+}