feat: improve model connections and settings workflow

Model settings can now duplicate saved connections with encrypted API-key copying, while settings navigation stays usable across long forms and preserves the separate Platform Features tabs. The assistant storage startup worker now gates historical migration and compaction on actual pending legacy data, so ordinary chat free pages do not reopen the migration screen. Desktop and Agent release metadata is prepared for 0.13.8 and 0.13.2.

Release note: 改进模型连接复制、长表单设置导航和历史数据迁移判断；普通聊天退出并重开后不再重复显示迁移页面。

src/shared/contracts.ts

@@ -617,11 +617,27 @@ export {
 export const defaultAnthropicMaximumOutputTokens = 32_000
 export const maximumModelOutputTokens = 10_000_000
 
+export const modelConnectionUrlSchema = z
+  .string()
+  .trim()
+  .min(1, '模型服务地址不能为空')
+  .max(2_048, '模型服务地址不能超过 2048 个字符')
+  .refine(
+    (value) => {
+      try {
+        return ['http:', 'https:'].includes(new URL(value).protocol)
+      } catch {
+        return false
+      }
+    },
+    '模型服务地址必须是完整的 HTTP 或 HTTPS 地址'
+  )
+
 const modelProfileInputSchema = z
   .object({
     id: modelProfileIdSchema,
     name: z.string().trim().min(1).max(64),
-    baseUrl: z.string().url().max(2_048),
+    baseUrl: modelConnectionUrlSchema,
     modelName: z
       .string()
       .trim()
@@ -647,7 +663,13 @@ const modelProfileInputSchema = z
     imageGenerationQuality: imageGenerationQualitySchema,
     requestHeaders: modelRequestHeadersSchema.optional(),
     requestBody: modelRequestBodySchema.optional(),
-    apiKey: modelApiKeyUpdateSchema
+    apiKey: z.union([
+      modelApiKeyUpdateSchema,
+      z.object({
+        action: z.literal('copy'),
+        sourceProfileId: modelProfileIdSchema
+      }).strict()
+    ])
   })
   .strict()
 
@@ -694,7 +716,7 @@ export const runtimeModelSourceSchema = z.discriminatedUnion('kind', [
 export const runtimeSettingsInputSchema = z
   .object({
     provider: runtimeProviderSchema,
-    modelBaseUrl: z.string().url().max(2_048),
+    modelBaseUrl: modelConnectionUrlSchema,
     modelName: z
       .string()
       .trim()
@@ -766,19 +788,6 @@ export const runtimeSettingsInputSchema = z
         message: '无认证模型连接不得配置 API Key'
       })
     }
-    const endpoints = settings.modelProfiles?.map((profile, index) => ({
-      path: ['modelProfiles', index, 'baseUrl'] as (string | number)[],
-      value: profile.baseUrl
-    })) ?? [{ path: ['modelBaseUrl'], value: settings.modelBaseUrl }]
-    for (const endpoint of endpoints) {
-      if (!['http:', 'https:'].includes(new URL(endpoint.value).protocol)) {
-        context.addIssue({
-          code: 'custom',
-          path: endpoint.path,
-          message: '模型服务地址必须使用 HTTP 或 HTTPS'
-        })
-      }
-    }
     if (settings.modelProfiles) {
       for (const [index, profile] of settings.modelProfiles.entries()) {
         if (