refactor: reorganize CSS and Tool Workshop page

- Extract styles.css into styles/ directory (tokens, global, utilities, syntax-highlight, pages)
- Extract ToolWorkshopPage into components:
  - ToolTypeListSidebar, ToolTypeEditorPanel, ToolWorkshopMobileView
  - use-tool-workshop hook for state management
- Slim ToolWorkshopPage from 1,269 to 110 lines

Quality gates: tsc --noEmit passes, npm run build passes

apps/web/src/styles/pages/ssh-keys.css

@@ -0,0 +1,25 @@
+/* SSH keys table responsive */
+.ssh-key-list {
+	display: flex;
+	flex-direction: column;
+	gap: var(--space-3);
+}
+
+.ssh-key-item {
+	display: flex;
+	flex-direction: column;
+	gap: var(--space-2);
+	padding: var(--space-4);
+	background: var(--bg);
+	border: 1px solid var(--border);
+	border-radius: 10px;
+}
+
+@media (min-width: 768px) {
+	.ssh-key-item {
+		flex-direction: row;
+		justify-content: space-between;
+		align-items: center;
+	}
+}
+