feat: add frosted glass appearance and improve local MCP recovery

Add an opt-in persistent frosted glass setting for the top bar and runtime checklist, with chat scrolling behind the header while preserving scroll anchors and window controls.

Retry transient local MCP initialization failures once after cleanup, include redacted connection diagnostics in feedback, and index lifecycle events to reduce execution statistics scans.

Release note: Add optional frosted glass appearance with chat visible behind the title bar; improve local tool connection recovery and diagnostic feedback.

src/main/desktop-diagnostics.ts

@@ -35,6 +35,7 @@ const allowedCodes = new Set([
   'desktop.startup.failed',
   'runtime.operation.failed',
   'runtime.run.failed',
+  'runtime.mcp.failed',
   'remote.connection.network',
   'remote.connection.host-invalidated',
   'remote.connection.host-identity',
@@ -68,6 +69,35 @@ export type DesktopDiagnosticComponent =
   | 'runtime'
   | 'remote-agent'
 
+export type DesktopMcpDiagnosticMetadata = Readonly<{
+  phase: 'request' | 'authentication' | 'session' | 'initialize' | 'tool-discovery' | 'connect' | 'disconnect'
+  category: 'http-rejection' | 'handler-failure' | 'transport-failure' | 'initialization-failure' | 'cleanup-failure' | 'cancelled'
+  elapsedMs: number
+  status?: number
+  correlationId?: string
+  attempt?: 1 | 2
+  kind?: 'builtin' | 'custom'
+}>
+
+function normalizeMcpMetadata(value: unknown): DesktopMcpDiagnosticMetadata | undefined {
+  if (!value || typeof value !== 'object') return undefined
+  const candidate = value as DesktopMcpDiagnosticMetadata
+  if (!['request', 'authentication', 'session', 'initialize', 'tool-discovery', 'connect', 'disconnect'].includes(candidate.phase) ||
+    !['http-rejection', 'handler-failure', 'transport-failure', 'initialization-failure', 'cleanup-failure', 'cancelled'].includes(candidate.category) ||
+    !Number.isSafeInteger(candidate.elapsedMs) || candidate.elapsedMs < 0) return undefined
+  return Object.freeze({
+    phase: candidate.phase,
+    category: candidate.category,
+    elapsedMs: candidate.elapsedMs,
+    ...(candidate.attempt === 1 || candidate.attempt === 2 ? { attempt: candidate.attempt } : {}),
+    ...(candidate.kind === 'builtin' || candidate.kind === 'custom' ? { kind: candidate.kind } : {}),
+    ...(Number.isInteger(candidate.status) && candidate.status! >= 100 && candidate.status! <= 599
+      ? { status: candidate.status } : {}),
+    ...(typeof candidate.correlationId === 'string' && /^sha256:[a-f0-9]{64}$/.test(candidate.correlationId)
+      ? { correlationId: candidate.correlationId } : {})
+  })
+}
+
 export type DesktopDiagnosticFailure = Readonly<{
   component: DesktopDiagnosticComponent
   stage: string
@@ -75,6 +105,7 @@ export type DesktopDiagnosticFailure = Readonly<{
   error: unknown
   reason?: string
   exitCode?: number
+  mcp?: DesktopMcpDiagnosticMetadata
 }>
 
 export type DesktopDiagnosticFailureObserver = (
@@ -90,6 +121,7 @@ export type DesktopDiagnosticRecord = Readonly<{
   message: string
   reason?: string
   exitCode?: number
+  mcp?: DesktopMcpDiagnosticMetadata
 }>
 
 export type DesktopDiagnosticsOptions = Readonly<{
@@ -178,6 +210,8 @@ export function normalizeDesktopDiagnosticRecord(
   const component = safeComponent(candidate.component)
   const stage = safeStage(candidate.stage)
   const code = safeCode(candidate.code)
+  const mcp = component === 'runtime' && code === 'runtime.mcp.failed'
+    ? normalizeMcpMetadata(candidate.mcp) : undefined
   const rendererGone = component === 'desktop' && stage === 'renderer' &&
     code === 'desktop.renderer.gone'
   return Object.freeze({
@@ -187,6 +221,7 @@ export function normalizeDesktopDiagnosticRecord(
     code,
     errorType: safeStoredErrorType(candidate.errorType),
     message: fixedMessage(component, stage),
+    ...(mcp ? { mcp } : {}),
     ...(rendererGone && typeof candidate.reason === 'string' &&
       rendererExitReasons.has(candidate.reason) ? { reason: candidate.reason } : {}),
     ...(rendererGone && Number.isSafeInteger(candidate.exitCode)
@@ -266,7 +301,8 @@ export class DesktopDiagnostics {
         code: failure.code,
         errorType: safeErrorType(failure.error),
         reason: failure.reason,
-        exitCode: failure.exitCode
+        exitCode: failure.exitCode,
+        mcp: failure.mcp
       })
       if (normalized === undefined) {
         return Promise.reject(