fix(share): 释放PixelMap/ImageSource + 指引监听 onDestroy 退订（code review C1/C2）

- C1: writeClipboardImage 在 finally 显式 pm.release()/source.release()，消除原生堆对象泄漏
- C2: 新增 guideCancelFn 字段；guide() 先退订悬挂监听再登记新监听、触发后清空；onDestroy() 退订；防用户不操作指引窗时 EventBus.once 永久悬挂
- I3: open 分支补注释说明乐观回传有意不等 openLink 完成

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feature_capabilities/src/main/ets/providers/ShareProvider.ets

@@ -41,6 +41,8 @@ export class ShareProvider implements CapabilityProvider {
   /** 落盘 + resultEvent 命名计数器（实例自增，避免 Math.random 串扰）。 */
   private seq: number = 0;
   private photoUploadCancel: (() => void) | undefined = undefined;
+  /** 当前指引窗一次性监听的退订函数（用户不操作时由 onDestroy/下一次 guide 退订，防悬挂泄漏）。 */
+  private guideCancelFn: (() => void) | undefined = undefined;
 
   constructor() {
     ShareProvider.instanceCount += 1;
@@ -62,6 +64,10 @@ export class ShareProvider implements CapabilityProvider {
       this.photoUploadCancel();
       this.photoUploadCancel = undefined;
     }
+    if (this.guideCancelFn !== undefined) {
+      this.guideCancelFn();
+      this.guideCancelFn = undefined;
+    }
   }
 
   // —— 入站 ——
@@ -195,9 +201,17 @@ export class ShareProvider implements CapabilityProvider {
   }
 
   private guide(bean: SharetypeBean, platform: string, kind: string, filePath: string): void {
+    // 退订上一个可能悬挂的指引监听（用户上次未操作就再次触发分享）。
+    if (this.guideCancelFn !== undefined) {
+      this.guideCancelFn();
+      this.guideCancelFn = undefined;
+    }
     this.seq += 1;
     const resultEvent: string = `share.guide.${this.instanceId}.${this.seq}`;
-    EventBus.once(resultEvent, (p) => this.onGuideAction(bean, platform, kind, filePath, p));
+    this.guideCancelFn = EventBus.once(resultEvent, (p) => {
+      this.guideCancelFn = undefined;
+      this.onGuideAction(bean, platform, kind, filePath, p);
+    });
     const req: ShareGuideRequest = { platform, contentKind: kind, resultEvent };
     EventBus.emit(ShareEvents.SHOW_GUIDE, req);
   }
@@ -212,6 +226,7 @@ export class ShareProvider implements CapabilityProvider {
     const reportType: number = bean.sharefriend === '1' ? 1 : 2;
     if (action === 'open') {
       this.openApp(uiCtx, platform);
+      // 乐观回传：不等 openLink 完成即视为已发起（契约 sharesuccess 仅微信完整）。
       if (platform === 'wechat') {
         this.reportResult(2, reportType);
       }
@@ -285,9 +300,13 @@ export class ShareProvider implements CapabilityProvider {
           .catch((e: BusinessError) => this.log.w(`clipboard image failed: ${e.code} ${e.message}`));
       } catch (e) {
         this.log.w(`clipboard image init failed: ${(e as Error).message}`);
+      } finally {
+        pm.release();
       }
     }).catch((e: BusinessError) => {
       this.log.w(`createPixelMap failed: ${e.code} ${e.message}`);
+    }).finally(() => {
+      source.release();
     });
   }