feat(logging-p0): add screenshot capture and browser console diagnostics for ERP errors

Enhance ERP automation error diagnostics by capturing PNG screenshots
on every error and forwarding browser console warnings/errors to the
structured logger. Includes automatic cleanup of old screenshots
aligned with the configured log retention period.

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

src/main/services/erp/page-diagnostics.ts

@@ -0,0 +1,50 @@
+/**
+ * Page Diagnostics
+ *
+ * Attaches browser console and error listeners to Playwright pages
+ * so that ERP-side JS errors are visible in the application log.
+ *
+ * Only warning and error level console messages are captured —
+ * ERP (YonBIP) outputs large volumes of info-level messages that
+ * would drown the log.
+ */
+
+import type { Page, BrowserContext } from 'playwright'
+import { createLogger } from '../logger'
+
+const log = createLogger('BrowserDiagnostics')
+
+/**
+ * Attach console and error listeners to a single page.
+ */
+export function attachPageDiagnostics(page: Page): void {
+  page.on('console', (msg) => {
+    const type = msg.type()
+    if (type !== 'warning' && type !== 'error') return
+
+    const location = msg.location()
+    log.error(`[Browser ${type}] ${msg.text()}`, {
+      pageUrl: page.url(),
+      consoleType: type,
+      location: location ? `${location.url}:${location.lineNumber}` : undefined
+    })
+  })
+
+  page.on('pageerror', (error) => {
+    log.error(`[Browser pageerror] ${error.message}`, {
+      pageUrl: page.url(),
+      error: error.message,
+      stack: error.stack
+    })
+  })
+}
+
+/**
+ * Attach diagnostics to all current and future pages in a browser context.
+ * Covers popups and pages opened by ERP automation.
+ */
+export function attachContextDiagnostics(context: BrowserContext): void {
+  context.on('page', (page) => {
+    attachPageDiagnostics(page)
+  })
+}