fix(project): 允许 fact_key 驼峰命名并澄清未绑定项目授权报错 (#200) (#217)

- fact_key 校验放开大写字母，支持驼峰命名（如 finding/info-disclosure-messageBundle）：
  - internal/database/project.go: 正则 ^[a-z0-9]... 改为 ^[a-zA-Z0-9]...，并更新错误提示
  - internal/project/fact_body_links.go: body 解析正则（依赖事实/相关 fact_key）同步放开大写
- authorizeProjectTool 区分「未绑定项目 / 查询出错 / 真实无权限」三种情况：
  未绑定项目时返回明确可执行提示，替代误导性的 no access to project
  - internal/app/mcp_authorization.go

Co-authored-by: sycmacmini <sycmacmini@sycmacminis-Mac-mini.local>

internal/app/mcp_authorization.go

@@ -382,7 +382,13 @@ func authorizeProjectTool(ctx context.Context, principal authctx.Principal, db *
 		return fmt.Errorf("no access to conversation %s", conversationID)
 	}
 	projectID, err := db.GetConversationProjectID(conversationID)
-	if err != nil || strings.TrimSpace(projectID) == "" || !db.UserCanAccessResource(principal.UserID, principal.ScopeFor(permission), "project", projectID) {
+	if err != nil {
+		return fmt.Errorf("no access to project: %w", err)
+	}
+	if strings.TrimSpace(projectID) == "" {
+		return fmt.Errorf("当前对话未绑定项目，无法使用项目黑板工具，请先在对话中选择项目或创建带项目的对话")
+	}
+	if !db.UserCanAccessResource(principal.UserID, principal.ScopeFor(permission), "project", projectID) {
 		return fmt.Errorf("no access to project %s", projectID)
 	}
 	return nil