refactor(vscode): share the cached-state retry schedule across providers

The staggered re-send lived as three near-identical private methods in
the chat view, agent manager, and session editor providers. One helper
now owns the delays, the connected gate, and the replaced-target guard;
the providers keep thin wrappers over their own panel/view identity.
Also restores the package.json trailing newline the branch dropped.

packages/vscode/package.json

@@ -252,4 +252,4 @@
     "react-dom": "^19.1.1",
     "yaml": "^2.8.1"
   }
-}
+}

packages/vscode/src/AgentManagerPanelProvider.ts

@@ -1,4 +1,5 @@
 import * as vscode from 'vscode';
+import { scheduleCachedStateRetries } from './webviewCachedStateRetry';
 import { handleBridgeMessage, type BridgeRequest, type BridgeResponse } from './bridge';
 import { getThemeKindName } from './theme';
 import type { OpenCodeManager, ConnectionStatus } from './opencode';
@@ -24,30 +25,16 @@ export class AgentManagerPanelProvider {
   private readonly _webviewDevServerUrl: string | null;
 
   /**
-   * The webview only leaves its initial loading screen once it receives a
-   * `connectionStatus: connected` message. VS Code drops postMessage calls
-   * made before the webview's acquireVsCodeApi bridge is ready (common in
-   * code-server / slow or flaky networks), so a single send can be lost
-   * forever. Re-send at staggered delays until the target panel is replaced.
+   * See webviewCachedStateRetry.ts — a single postMessage can be dropped
+   * before the webview bridge is ready, leaving the loading screen stuck.
    */
   private _scheduleCachedStateRetries(targetPanel: vscode.WebviewPanel | undefined): void {
-    if (this._cachedStatus !== 'connected') {
-      return;
-    }
-    const panel = targetPanel ?? this._panel;
-    if (!panel) {
-      return;
-    }
-    const delaysMs = [500, 1500, 3500, 7000, 12000, 20000];
-    for (const delayMs of delaysMs) {
-      setTimeout(() => {
-        // Only re-send if this exact panel is still the active one.
-        if (this._panel !== panel) {
-          return;
-        }
-        this._sendCachedState();
-      }, delayMs);
-    }
+    scheduleCachedStateRetries({
+      target: targetPanel ?? this._panel,
+      getCurrent: () => this._panel,
+      isConnected: () => this._cachedStatus === 'connected',
+      send: () => this._sendCachedState(),
+    });
   }
 
   constructor(

packages/vscode/src/ChatViewProvider.ts

@@ -1,4 +1,5 @@
 import * as vscode from 'vscode';
+import { scheduleCachedStateRetries } from './webviewCachedStateRetry';
 import { handleBridgeMessage, type BridgeRequest, type BridgeResponse } from './bridge';
 import { getThemeKindName } from './theme';
 import type { OpenCodeManager, ConnectionStatus } from './opencode';
@@ -59,30 +60,16 @@ export class ChatViewProvider implements vscode.WebviewViewProvider {
   private readonly _MAX_RETRIES = 3;
 
   /**
-   * The webview only leaves its initial loading screen once it receives a
-   * `connectionStatus: connected` message. VS Code drops postMessage calls
-   * made before the webview's acquireVsCodeApi bridge is ready (common in
-   * code-server / slow or flaky networks), so a single send can be lost
-   * forever. Re-send at staggered delays until the target view is replaced.
+   * See webviewCachedStateRetry.ts — a single postMessage can be dropped
+   * before the webview bridge is ready, leaving the loading screen stuck.
    */
   private _scheduleCachedStateRetries(targetView: vscode.WebviewView | undefined): void {
-    if (this._cachedStatus !== 'connected') {
-      return;
-    }
-    const view = targetView ?? this._view;
-    if (!view) {
-      return;
-    }
-    const delaysMs = [500, 1500, 3500, 7000, 12000, 20000];
-    for (const delayMs of delaysMs) {
-      setTimeout(() => {
-        // Only re-send if this exact view is still the active one.
-        if (this._view !== view) {
-          return;
-        }
-        this._sendCachedState();
-      }, delayMs);
-    }
+    scheduleCachedStateRetries({
+      target: targetView ?? this._view,
+      getCurrent: () => this._view,
+      isConnected: () => this._cachedStatus === 'connected',
+      send: () => this._sendCachedState(),
+    });
   }
 
   private _createMessageId(): string {

packages/vscode/src/SessionEditorPanelProvider.ts

@@ -1,4 +1,5 @@
 import * as vscode from 'vscode';
+import { scheduleCachedStateRetries } from './webviewCachedStateRetry';
 import { handleBridgeMessage, type BridgeRequest, type BridgeResponse } from './bridge';
 import { getThemeKindName } from './theme';
 import type { OpenCodeManager, ConnectionStatus } from './opencode';
@@ -50,26 +51,16 @@ export class SessionEditorPanelProvider {
   private readonly _webviewDevServerUrl: string | null;
 
   /**
-   * The webview only leaves its initial loading screen once it receives a
-   * `connectionStatus: connected` message. VS Code drops postMessage calls
-   * made before the webview's acquireVsCodeApi bridge is ready (common in
-   * code-server / slow or flaky networks), so a single send can be lost
-   * forever. Re-send at staggered delays until the target panel is replaced.
+   * See webviewCachedStateRetry.ts — a single postMessage can be dropped
+   * before the webview bridge is ready, leaving the loading screen stuck.
    */
   private _scheduleCachedStateRetries(panelId: string, entry: SessionPanelState): void {
-    if (this._cachedStatus !== 'connected') {
-      return;
-    }
-    const delaysMs = [500, 1500, 3500, 7000, 12000, 20000];
-    for (const delayMs of delaysMs) {
-      setTimeout(() => {
-        // Only re-send if this exact panel is still registered.
-        if (this._panels.get(panelId)?.panel !== entry.panel) {
-          return;
-        }
-        this._sendCachedStateToPanel(entry);
-      }, delayMs);
-    }
+    scheduleCachedStateRetries({
+      target: entry.panel,
+      getCurrent: () => this._panels.get(panelId)?.panel,
+      isConnected: () => this._cachedStatus === 'connected',
+      send: () => this._sendCachedStateToPanel(entry),
+    });
   }
 
   constructor(

packages/vscode/src/webviewCachedStateRetry.ts

@@ -0,0 +1,31 @@
+/**
+ * The webview only leaves its initial loading screen once it receives a
+ * `connectionStatus: connected` message. VS Code drops postMessage calls made
+ * before the webview's acquireVsCodeApi bridge is ready (common in
+ * code-server / slow or flaky networks), so a single send can be lost
+ * forever. Re-sending the cached state at staggered delays bounds the wait
+ * without needing a webview-side ack protocol; the payload is idempotent
+ * (connection status + window focus), so duplicate deliveries are harmless.
+ */
+const CACHED_STATE_RETRY_DELAYS_MS = [500, 1500, 3500, 7000, 12000, 20000];
+
+export function scheduleCachedStateRetries<Target>(input: {
+  /** The panel/view the retries belong to. */
+  target: Target | undefined;
+  /** Reads the provider's CURRENT panel/view, so a replaced target stops its stale retries. */
+  getCurrent: () => Target | undefined;
+  /** Retries only make sense for the connected transition. */
+  isConnected: () => boolean;
+  /** Re-sends the provider's cached state. */
+  send: () => void;
+}): void {
+  if (!input.isConnected()) return;
+  const target = input.target;
+  if (!target) return;
+  for (const delayMs of CACHED_STATE_RETRY_DELAYS_MS) {
+    setTimeout(() => {
+      if (input.getCurrent() !== target) return;
+      input.send();
+    }, delayMs);
+  }
+}