fix(error): add global error handler, fix stores and dispatcher

- Global unhandledrejection handler with IPC+network filtering
- Agent dispatcher heartbeat uses handleInfraError (was fire-and-forget)
- All stores: layout, workspace, anchors, theme, plugins, machines,
  wake-scheduler — silent failures replaced with handleInfraError
- initGlobalErrorHandler() called in App.svelte onMount

src/lib/stores/layout.svelte.ts

@@ -9,6 +9,7 @@ import {
   updateSessionGroup,
   type PersistedSession,
 } from '../adapters/session-bridge';
+import { handleInfraError } from '../utils/handle-error';
 
 export type LayoutPreset = '1-col' | '2-col' | '3-col' | '2x2' | 'master-stack';
 
@@ -46,14 +47,14 @@ function persistSession(pane: Pane): void {
     created_at: now,
     last_used_at: now,
   };
-  saveSession(session).catch(e => console.warn('Failed to persist session:', e));
+  saveSession(session).catch(e => handleInfraError(e, 'layout.persistSession'));
 }
 
 function persistLayout(): void {
   saveLayout({
     preset: activePreset,
     pane_ids: panes.map(p => p.id),
-  }).catch(e => console.warn('Failed to persist layout:', e));
+  }).catch(e => handleInfraError(e, 'layout.persistLayout'));
 }
 
 // --- Public API ---
@@ -84,14 +85,14 @@ export function removePane(id: string): void {
     focusedPaneId = panes.length > 0 ? panes[0].id : null;
   }
   autoPreset();
-  deleteSession(id).catch(e => console.warn('Failed to delete session:', e));
+  deleteSession(id).catch(e => handleInfraError(e, 'layout.deleteSession'));
   persistLayout();
 }
 
 export function focusPane(id: string): void {
   focusedPaneId = id;
   panes = panes.map(p => ({ ...p, focused: p.id === id }));
-  touchSession(id).catch(e => console.warn('Failed to touch session:', e));
+  touchSession(id).catch(e => handleInfraError(e, 'layout.touchSession'));
 }
 
 export function focusPaneByIndex(index: number): void {
@@ -109,7 +110,7 @@ export function renamePaneTitle(id: string, title: string): void {
   const pane = panes.find(p => p.id === id);
   if (pane) {
     pane.title = title;
-    updateSessionTitle(id, title).catch(e => console.warn('Failed to update title:', e));
+    updateSessionTitle(id, title).catch(e => handleInfraError(e, 'layout.updateTitle'));
   }
 }
 
@@ -117,7 +118,7 @@ export function setPaneGroup(id: string, group: string): void {
   const pane = panes.find(p => p.id === id);
   if (pane) {
     pane.group = group || undefined;
-    updateSessionGroup(id, group).catch(e => console.warn('Failed to update group:', e));
+    updateSessionGroup(id, group).catch(e => handleInfraError(e, 'layout.updateGroup'));
   }
 }
 
@@ -156,7 +157,7 @@ export async function restoreFromDb(): Promise<void> {
       focusPane(panes[0].id);
     }
   } catch (e) {
-    console.warn('Failed to restore sessions from DB:', e);
+    handleInfraError(e, 'layout.restoreFromDb');
   }
 }