feat(ui): modernize CharacterModals with glassmorphism design and add save API

UI Improvements:
- Redesign modal wrapper with gradient background and decorative glow effects
- Apply glassmorphism styling (backdrop-blur, white/10 borders, rounded-2xl/3xl)
- Update form inputs with modern styling (rounded-xl, focus rings, transitions)
- Enhance range slider with gradient thumb and dynamic fill
- Improve tag badges with border accents
- Add glow drop-shadow utilities in tailwind config

API Additions:
- Add db-save-character-details IPC handler in database-handlers.js
  - Syncs profile fields (name, nickname, relationship_label, etc.) to characters table
- Expose saveCharacterDetails in preload.js
- Add graceful fallback with user-friendly error message if API not loaded

Author: hhh2210

desktop/src/core/modules/ipc-handlers/database-handlers.js

@@ -177,6 +177,46 @@ export function registerDatabaseHandlers({ db }) {
     }
   });
 
+  ipcMain.handle('db-save-character-details', (event, characterId, details) => {
+    try {
+      const normalizedDetails = {
+        ...(details || {}),
+        character_id: characterId,
+        updated_at: Date.now()
+      };
+
+      // 1) 先保存详情表
+      const ok = db.saveCharacterDetails(characterId, normalizedDetails);
+
+      // 2) 如果详情里包含 profile，则同步更新 characters 主表，避免 UI 列表与详情不一致
+      const profile = normalizedDetails?.profile;
+      if (profile && typeof profile === 'object') {
+        const updates = {};
+        const allowed = [
+          'name',
+          'nickname',
+          'relationship_label',
+          'avatar_color',
+          'affinity',
+          'notes'
+        ];
+        for (const key of allowed) {
+          if (Object.prototype.hasOwnProperty.call(profile, key)) {
+            updates[key] = profile[key];
+          }
+        }
+        if (Object.keys(updates).length > 0) {
+          db.updateCharacter(characterId, updates);
+        }
+      }
+
+      return !!ok;
+    } catch (error) {
+      console.error('Error saving character details:', error);
+      return false;
+    }
+  });
+
   ipcMain.handle(
     'db-update-character-details-custom-fields',
     (event, characterId, customFields) => {

desktop/src/preload.js

@@ -144,6 +144,8 @@ contextBridge.exposeInMainWorld('electronAPI', {
   getConversationAIData: (conversationId) => ipcRenderer.invoke('db-get-conversation-ai-data', conversationId),
   selectActionSuggestion: (payload) => ipcRenderer.invoke('db-select-action-suggestion', payload),
   getCharacterDetails: (characterId) => ipcRenderer.invoke('db-get-character-details', characterId),
+  saveCharacterDetails: (characterId, details) =>
+    ipcRenderer.invoke('db-save-character-details', characterId, details),
   updateCharacterDetailsCustomFields: (characterId, customFields) => ipcRenderer.invoke('db-update-character-details-custom-fields', characterId, customFields),
   regenerateCharacterDetails: (characterId) => ipcRenderer.invoke('db-regenerate-character-details', characterId),
   deleteConversation: (conversationId) => ipcRenderer.invoke('db-delete-conversation', conversationId),