fix: reduce supervisor stalls and preserve task delivery

Load Supervisor graphs only when opened, preserve source details on demand, reuse indexed story digests and window selection lists without losing keyboard or focus behavior. Route heavy UI reads through the existing worker, batch scoped queries and construct each publication snapshot once.

Keep remote cancellation responsive during model-route cleanup, remove late routes and retain reported usage after response-cap cancellation. Preserve Telegram pending replies through polling conflicts, show delivery errors and honor the final rate-limit cooldown.

Schema 62 adds lookup indexes without rewriting user content; older clients cannot open upgraded data. Large review publication still blocks Main and remains documented follow-up work. Record the future storage-service direction without performing the architecture migration.

Validation: exact staged code passed isolated full tests (6212 passed, 87 skipped), typecheck and lint. Three-round source performance comparisons, SQLite migration equivalence, native Electron interaction checks and current-source Linux x64 Host validation completed; eight external text-model requests.

Release note: Supervisor opens reviews without loading the entire graph, keeps long selection lists responsive and preserves details and keyboard navigation. Remote cancellation and Telegram reply recovery are more reliable; remote fixes require an Agent build containing this change.

docs/features/telegram-channel/prd.md

@@ -138,6 +138,8 @@ Token 使用现有加密凭据存储，保存后不在普通设置快照中返
 
 已生成并保存的结果沿用现有发件箱有限重试，发送失败与任务执行失败分别记录。补发回复不重新调用模型或重跑任务。用户阻止 Bot 等不可恢复错误应停止无效重试。
 
+已有 webhook 或另一实例占用轮询时，已确认 Bot 身份且目标匹配的待发回复仍可发送；接收冲突本身不能永久终止这些回复。发送内部重试达到上限后，发件箱的下一次尝试仍须遵守最近一次 429 响应的等待时间，停用可取消等待。
+
 同一驱动实例内且分段进度仍在缓存时，多段回复从未发送部分继续。进度不跨重启持久化，重启或缓存淘汰后补发可能重复已发送段落；网络中断造成平台接收结果不明时也可能重复。首版不承诺平台级发送幂等。
 
 ### FR-10 启停与历史保留
@@ -162,6 +164,8 @@ Telegram 待接收更新最多保留 24 小时，超过平台保留期的离线
 
 状态和错误推送只更新状态区域，不覆盖尚未保存的 Token 或白名单草稿。解决轮询冲突后可重新保存当前配置以启动连接；单独测试连接成功不改变接收状态。
 
+接收正常而结果发送失败时，保留已连接状态并显示脱敏的发送错误。后续健康轮询不清除发送提示，投递成功后清除；接收也发生错误时优先展示接收原因，恢复后保留尚未清除的发送提示。
+
 状态通过文字表达，不能只靠颜色。错误保留可操作原因，如 Token 无效、网络不可达、webhook 占用或另一实例正在轮询。测试成功、发送失败和模型失败使用各自准确文案，避免统一显示“连接失败”。
 
 界面沿用 [UI-DESIGN.md](../../../UI-DESIGN.md) 的控件、通知、键盘和可访问性规则，不新增独立视觉体系。