feat(pilot): EscalateInterceptDialog — fourth 'partial' choice

Closes the gap Phase 8 final review flagged. When a fix is in
applied_partial state and the engineer escalates, the intercept no
longer forces them to approximate with didn't-work/worked/never-applied.

AssistantChatPage's handleInterceptChoice (Task 13) already dispatches
to patchOutcome for any FixOutcome value, so no handler change is
needed — the type already supports applied_partial.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/components/pilot/EscalateInterceptDialog.tsx

@@ -8,7 +8,7 @@
  * Visual reference: docs/FlowAssist_Migration/mockups/07-verify-states.html
  * (panel C).
  */
-import { X, AlertCircle, Check } from 'lucide-react'
+import { X, AlertCircle, Check, Info } from 'lucide-react'
 import type { FixOutcome } from '@/api/sessionSuggestedFixes'
 
 export type InterceptChoice = FixOutcome | 'never_applied'
@@ -53,6 +53,13 @@ export function EscalateInterceptDialog({
             <span className="flex-1">The fix didn&apos;t work</span>
             <span className="text-[10.5px] text-muted-foreground font-mono px-1.5 py-[2px] rounded bg-white/[0.05]">↵</span>
           </button>
+          <button
+            onClick={() => onChoose('applied_partial')}
+            className="flex items-center gap-2.5 px-3 py-2.5 rounded-lg border border-white/10 bg-elevated text-[12.5px] text-primary hover:bg-sidebar transition-colors text-left"
+          >
+            <Info size={13} strokeWidth={2} />
+            <span className="flex-1">I applied some of it — partial</span>
+          </button>
           <button
             onClick={() => onChoose('applied_success')}
             className="flex items-center gap-2.5 px-3 py-2.5 rounded-lg border border-white/10 bg-elevated text-[12.5px] text-primary hover:bg-sidebar transition-colors text-left"