feat: AI 提示词模块化 + AI 同意门控 + AI 草稿存储 + 意图路由 + 医疗引用知识库 + 多页面 UI 优化

- AI 提示词拆分为 markdown 模块（Prompts/global + modules + rag + router）
- 新增 AI 同意门控（用户需同意后才能使用 AI 功能）
- 新增 AI 录入草稿存储（AiEntryDraftContracts/EfAiEntryDraftStore/AiEntryDraftRecord）
- 新增 AI 意图路由（ai_intent_router）
- 新增医疗引用知识库（MedicalCitationKnowledge）
- 重构 prompt_manager 和 ai_chat_endpoints
- 优化聊天/趋势/档案/抽屉/医生端等多个页面 UI
- 新增 agent 插画和趋势指标图标资源
- 删除 HANDOFF-2026-07-17.md

backend/src/Health.WebApi/Endpoints/user_endpoints.cs

@@ -20,11 +20,12 @@ public static class UserEndpoints
             var birthDate = DateOnly.TryParse(req.BirthDate, out var parsed) ? parsed : (DateOnly?)null;
             var updated = await users.UpdateProfileAsync(
                 GetUserId(http),
-                new UserProfileUpdateRequest(req.Name, req.Gender, birthDate),
+                new UserProfileUpdateRequest(req.Name, req.Gender, birthDate, req.AvatarUrl),
                 ct);
             if (!updated) return Results.Ok(new { code = 40004, message = "用户不存在" });
 
-            return Results.Ok(new { code = 0, data = new { success = true }, message = (string?)null });
+            var profile = await users.GetProfileAsync(GetUserId(http), ct);
+            return Results.Ok(new { code = 0, data = profile, message = (string?)null });
         });
 
         group.MapGet("/health-archive", async (HttpContext http, IHealthArchiveService archives, CancellationToken ct) =>
@@ -66,7 +67,7 @@ public static class UserEndpoints
         Guid.TryParse(http.User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value, out var id) ? id : Guid.Empty;
 }
 
-public sealed record UpdateProfileRequest(string? Name, string? Gender, string? BirthDate);
+public sealed record UpdateProfileRequest(string? Name, string? Gender, string? BirthDate, string? AvatarUrl);
 public sealed record UpdateArchiveRequest(
     string? Diagnosis, string? SurgeryType, string? SurgeryDate,
     List<string>? Allergies, List<string>? DietRestrictions,