Surface preflight diagnosis on Patrol readiness banner

The readiness banner previously rendered only the summary string
("Provider connection issue (last preflight 2h ago)"), even though
the underlying payload already carried the provider, model, preflight
duration, tool-call observation, and recommendation. Operators had to
open dev tools to find out which provider failed and what to check.

Now the banner inlines:

  - Provider and model that preflight tried to reach
  - Preflight duration and whether a tool call was observed
  - The preflight recommendation text

The state hook gains a patrolPreflight memo that reads from the same
AISettings payload the rest of the patrol surface already consumes.

frontend-modern/src/features/patrol/PatrolIntelligenceBanners.tsx

@@ -3,9 +3,19 @@ import ShieldAlertIcon from 'lucide-solid/icons/shield-alert';
 import SettingsIcon from 'lucide-solid/icons/settings';
 import { presentationPolicyHidesUpgradePrompts } from '@/stores/sessionPresentationPolicy';
 import { formatRelativeTime } from '@/utils/format';
+import { getAIProviderDisplayName } from '@/utils/aiProviderPresentation';
 import { PATROL_PROVIDER_SETTINGS_ACTION } from '@/utils/patrolRuntimeActions';
 import type { PatrolIntelligenceState } from './usePatrolIntelligenceState';
 
+// Strip a provider prefix ("deepseek:deepseek-v4-flash" -> "deepseek-v4-flash")
+// so the model id reads cleanly to operators without losing the provider
+// label that's already rendered alongside it.
+function modelIdWithoutProviderPrefix(modelId: string | undefined): string {
+  if (!modelId) return '';
+  const colonIndex = modelId.indexOf(':');
+  return colonIndex > 0 ? modelId.substring(colonIndex + 1) : modelId;
+}
+
 export function PatrolIntelligenceBanners(props: { state: PatrolIntelligenceState }) {
   const state = props.state;
 
@@ -98,6 +108,65 @@ export function PatrolIntelligenceBanners(props: { state: PatrolIntelligenceStat
                 >
                   {state.patrolReadiness()?.summary}
                 </p>
+                {/* Concrete diagnosis: which provider and model failed, and
+                    the preflight recommendation. Without these the banner
+                    summary alone ("Provider connection issue") leaves the
+                    operator with nothing actionable. */}
+                <Show
+                  when={
+                    state.patrolReadiness()?.provider || state.patrolReadiness()?.model
+                  }
+                >
+                  <p
+                    class={`text-xs mt-1 ${
+                      state.patrolReadiness()?.status === 'not_ready'
+                        ? 'text-red-700 dark:text-red-200'
+                        : 'text-amber-700 dark:text-amber-300'
+                    }`}
+                  >
+                    <Show when={state.patrolReadiness()?.provider}>
+                      <span class="font-medium">Provider:</span>{' '}
+                      {getAIProviderDisplayName(state.patrolReadiness()!.provider!)}
+                    </Show>
+                    <Show
+                      when={
+                        state.patrolReadiness()?.provider && state.patrolReadiness()?.model
+                      }
+                    >
+                      {' · '}
+                    </Show>
+                    <Show when={state.patrolReadiness()?.model}>
+                      <span class="font-medium">Model:</span>{' '}
+                      <code class="font-mono">
+                        {modelIdWithoutProviderPrefix(state.patrolReadiness()!.model)}
+                      </code>
+                    </Show>
+                    <Show
+                      when={
+                        state.patrolPreflight()?.duration_ms !== undefined &&
+                        state.patrolPreflight()!.duration_ms > 0
+                      }
+                    >
+                      {' · '}
+                      <span class="font-medium">Preflight:</span>{' '}
+                      {(state.patrolPreflight()!.duration_ms / 1000).toFixed(1)}s
+                      <Show when={state.patrolPreflight()?.tool_call_observed === false}>
+                        , no tool call observed
+                      </Show>
+                    </Show>
+                  </p>
+                </Show>
+                <Show when={state.patrolPreflight()?.recommendation}>
+                  <p
+                    class={`text-xs mt-1 italic ${
+                      state.patrolReadiness()?.status === 'not_ready'
+                        ? 'text-red-700 dark:text-red-200'
+                        : 'text-amber-700 dark:text-amber-300'
+                    }`}
+                  >
+                    {state.patrolPreflight()!.recommendation}
+                  </p>
+                </Show>
               </div>
             </div>
             <a

frontend-modern/src/features/patrol/usePatrolIntelligenceState.ts

@@ -505,6 +505,11 @@ export function usePatrolIntelligenceState() {
   );
   const blockedAt = createMemo(() => patrolStatus()?.blocked_at);
   const patrolReadiness = createMemo(() => patrolStatus()?.readiness ?? null);
+  // Pulse records the last preflight result on AISettings.patrol_preflight
+  // (provider/model/duration/recommendation) so we can surface a concrete
+  // diagnosis on the readiness banner instead of a one-line "Provider
+  // connection issue" that forces operators to spelunk dev tools.
+  const patrolPreflight = createMemo(() => aiRuntimeSettings()?.patrol_preflight ?? null);
   const readinessBlocksPatrol = createMemo(() => patrolReadiness()?.status === 'not_ready');
   const showBlockedBanner = createMemo(() => runtimeState() === 'blocked');
   const showReadinessBanner = createMemo(() => {
@@ -934,6 +939,7 @@ export function usePatrolIntelligenceState() {
     patrolAnomalyTriggers,
     patrolInterval,
     patrolModel,
+    patrolPreflight,
     patrolReadiness,
     patrolRunHistory,
     runtimeState,