feat(advisor): topic threads, per-question delete/copy, fullscreen

Adds case management to the Compliance Advisor widget.

- topic threads: cases group into threads; the left menu shows each
  thread's first question as the Thema with expandable follow-ups.
  Send = follow-up to the active thread (carries the thread's prior Q&A
  as history for contextual answers); "+" starts a new topic.
- delete: a trash action per question (menu + stacked view).
- copy: single Q&A (question + answer + evidence + footnotes) or a whole
  thread, as Markdown to the clipboard (pure formatters in copy.ts).
- fullscreen: compact -> panel -> fullscreen view.
- route.ts consumes an optional bounded `history` so follow-ups are
  contextual for both the widget and the workspace consumer.

Tests: copy formatter unit tests + Playwright specs (threads/new-topic,
delete, fullscreen, copy affordance). No deploy.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

admin-compliance/components/sdk/advisor/EvidenceWorkspace.tsx

@@ -1,7 +1,7 @@
 'use client'
 
-import { useEffect, useRef, useState } from 'react'
-import type { AdvisorCase } from './useAdvisorCase'
+import { useEffect, useRef } from 'react'
+import type { AdvisorCase, AdvisorThread } from './useAdvisorCase'
 import { StickyQuestion } from './StickyQuestion'
 import { AdvisorEmptyState } from './EmptyState'
 import { CaseView, LoadingDots, ErrorBox } from './CaseView'
@@ -11,36 +11,41 @@ import { EvidencePane } from './EvidencePane'
 import { VisualEvidencePane } from './VisualEvidencePane'
 import { FootnotesPane } from './FootnotesPane'
 import { Markdown } from './Markdown'
+import { ThreadMenu } from './ThreadMenu'
 import { useCitationHighlight } from './useCitationHighlight'
 
 /**
- * Advisor body as a series of CASES.
- * - Narrow: stacked cases with a pinned last question.
- * - Wide: 3-column Case Workspace — question+summary (left) | answer/clarify (center) | evidence (right).
+ * Advisor body as topic THREADS of cases.
+ * - Narrow: stacked cases with a pinned last question; per-case copy + delete.
+ * - Wide/fullscreen: 3-column Case Workspace — topic tree (left) | answer/clarify (center) | evidence (right).
  */
 export function EvidenceWorkspace({
   cases,
+  threads,
   expanded,
   busy,
+  activeCaseId,
   exampleQuestions,
   onExample,
   onSelectContext,
+  onSelectCase,
+  onRemove,
 }: {
   cases: AdvisorCase[]
+  threads: AdvisorThread[]
   expanded: boolean
   busy: boolean
+  activeCaseId: string | null
   exampleQuestions: string[]
   onExample: (q: string) => void
   onSelectContext: (caseId: string, ctx: string) => void
+  onSelectCase: (id: string) => void
+  onRemove: (id: string) => void
 }) {
-  const [activeId, setActiveId] = useState<string | null>(null)
   const endRef = useRef<HTMLDivElement>(null)
   const latest = cases[cases.length - 1]
-  const active = cases.find((c) => c.id === activeId) ?? latest
+  const active = cases.find((c) => c.id === activeCaseId) ?? latest
 
-  useEffect(() => {
-    setActiveId(null)
-  }, [cases.length])
   useEffect(() => {
     if (!expanded) endRef.current?.scrollIntoView({ behavior: 'smooth' })
   }, [cases.length, expanded])
@@ -68,6 +73,7 @@ export function EvidenceWorkspace({
               busy={busy}
               showQuestion={i !== cases.length - 1}
               onSelectContext={(ctx) => onSelectContext(c.id, ctx)}
+              onRemove={() => onRemove(c.id)}
             />
           ))}
           <div ref={endRef} />
@@ -78,27 +84,19 @@ export function EvidenceWorkspace({
 
   const r = active?.response
   return (
-    <div className="grid min-h-0 flex-1 grid-cols-[220px_1fr_320px] divide-x divide-gray-200 overflow-hidden">
+    <div className="grid min-h-0 flex-1 grid-cols-[260px_1fr_320px] divide-x divide-gray-200 overflow-hidden">
       <aside className="min-h-0 overflow-y-auto bg-indigo-50/40 p-3">
-        <div className="text-[10px] font-semibold uppercase tracking-wide text-indigo-400">Frage</div>
-        <div className="mb-3 text-sm font-medium text-gray-800">{active?.question}</div>
-        {answer && <EvidenceSummary response={answer} />}
-        {cases.length > 1 && (
-          <div className="mt-4">
-            <div className="mb-1 text-[10px] font-semibold uppercase tracking-wide text-gray-400">Verlauf</div>
-            <div className="space-y-1">
-              {cases.map((c) => (
-                <button
-                  key={c.id}
-                  onClick={() => setActiveId(c.id)}
-                  className={`block w-full truncate rounded px-2 py-1 text-left text-[11px] ${
-                    c.id === active?.id ? 'bg-indigo-100 text-indigo-800' : 'text-gray-600 hover:bg-gray-100'
-                  }`}
-                >
-                  {c.question}
-                </button>
-              ))}
-            </div>
+        <ThreadMenu
+          threads={threads}
+          activeCaseId={active?.id ?? null}
+          onSelectCase={onSelectCase}
+          onRemove={onRemove}
+        />
+        {active && (
+          <div className="mt-3 border-t border-indigo-100 pt-3">
+            <div className="text-[10px] font-semibold uppercase tracking-wide text-indigo-400">Aktive Frage</div>
+            <div className="mb-3 text-sm font-medium text-gray-800">{active.question}</div>
+            {answer && <EvidenceSummary response={answer} />}
           </div>
         )}
       </aside>