feat(webui): Add Models tab and refactor model configuration

- Add standalone Models tab with real-time quota/status display
- Move model identity table from Dashboard to Models tab
- Slim down Dashboard to KPI cards and charts only
- Dashboard charts now use unfiltered data (independent of Models filters)

Settings > Models improvements:
- Remove redundant Alias column (only Mapping is functional)
- Fix column misalignment bug (empty td)
- Add column widths and hidden row opacity styling
- Single row edit constraint (only one Mapping editable at a time)
- showHiddenModels toggle now only affects Settings (not Models tab)
- Update description text to match current functionality

i18n:
- Add 'models' and 'modelsPageDesc' keys (EN/ZH)
- Add 'modelMappingHint' for Claude CLI guidance
- Update 'modelsDesc' to reflect new functionality

public/js/components/models.js

@@ -0,0 +1,58 @@
+/**
+ * Models Component
+ * Displays model quota/status list
+ * Registers itself to window.Components for Alpine.js to consume
+ */
+window.Components = window.Components || {};
+
+window.Components.models = () => ({
+    init() {
+        // Ensure data is fetched when this tab becomes active
+        this.$watch('$store.global.activeTab', (val) => {
+            if (val === 'models') {
+                // Trigger recompute to ensure filters are applied
+                this.$nextTick(() => {
+                    Alpine.store('data').computeQuotaRows();
+                });
+            }
+        });
+
+        // Initial compute if already on models tab
+        if (this.$store.global.activeTab === 'models') {
+            this.$nextTick(() => {
+                Alpine.store('data').computeQuotaRows();
+            });
+        }
+    },
+
+    /**
+     * Update model configuration (Pin/Hide quick actions)
+     * @param {string} modelId - The model ID to update
+     * @param {object} configUpdates - Configuration updates (pinned, hidden)
+     */
+    async updateModelConfig(modelId, configUpdates) {
+        const store = Alpine.store('global');
+        try {
+            const { response, newPassword } = await window.utils.request('/api/models/config', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ modelId, config: configUpdates })
+            }, store.webuiPassword);
+
+            if (newPassword) store.webuiPassword = newPassword;
+
+            if (!response.ok) {
+                throw new Error('Failed to update model config');
+            }
+
+            // Optimistic update
+            Alpine.store('data').modelConfig[modelId] = {
+                ...Alpine.store('data').modelConfig[modelId],
+                ...configUpdates
+            };
+            Alpine.store('data').computeQuotaRows();
+        } catch (e) {
+            store.showToast('Failed to update: ' + e.message, 'error');
+        }
+    }
+});