feat(J): Phase J Self-Improvement Plugin — controlled improvement loop

- New self_improvement plugin: models, services, routes, plugin
- 4 SQLAlchemy models: ImprovementSignal, ImprovementPattern, ImprovementProposal, ImpactMeasurement
- Migration 0132: 4 tables with RLS
- Services: collect_signals, detect_patterns, create_proposal, evaluate_proposal, request_approval, activate_proposal, rollback_proposal, measure_impact
- 11 API routes under /api/v1/improvement/
- Frontend: improvement.ts API client, ImprovementPanel.tsx in AISidebar proactive tab
- 24/24 integration tests pass
- Fix: __init__.py imports Plugin class for discover_builtins() (self_improvement + knowledge)
- Fix: automation plugin register_plugin_contributions skips when no tenant exists

frontend/src/components/ai/ImprovementPanel.tsx

@@ -0,0 +1,238 @@
+/**
+ * Improvement Panel — shows signals, patterns, and proposals in the AISidebar proactive tab.
+ * Builds on existing SuggestionList pattern.
+ */
+
+import { useState } from 'react';
+import { useSignals, useCollectSignals, usePatterns, useDetectPatterns, useProposals, useEvaluateProposal, useActivateProposal, useRollbackProposal, useMeasureImpact } from '@/api/improvement';
+import { TrendingUp, AlertCircle, CheckCircle, RefreshCw, Play, RotateCcw, BarChart3 } from 'lucide-react';
+
+type SubView = 'signals' | 'patterns' | 'proposals';
+
+export function ImprovementPanel() {
+  const [subView, setSubView] = useState<SubView>('signals');
+
+  return (
+    <div className="flex flex-col h-full" data-testid="improvement-panel">
+      {/* Sub-tab selector */}
+      <div className="flex gap-1 px-3 py-2 border-b border-secondary-100">
+        {([
+          { key: 'signals' as const, label: 'Signale', icon: AlertCircle },
+          { key: 'patterns' as const, label: 'Muster', icon: TrendingUp },
+          { key: 'proposals' as const, label: 'Vorschläge', icon: CheckCircle },
+        ]).map(opt => (
+          <button
+            key={opt.key}
+            onClick={() => setSubView(opt.key)}
+            className={`px-3 py-1 rounded-full text-xs font-medium whitespace-nowrap transition-colors flex items-center gap-1 ${
+              subView === opt.key
+                ? 'bg-primary-500 text-white'
+                : 'bg-secondary-100 text-secondary-600 hover:bg-secondary-200'
+            }`}
+            aria-label={opt.label}
+          >
+            <opt.icon className="w-3 h-3" aria-hidden="true" strokeWidth={2} />
+            {opt.label}
+          </button>
+        ))}
+      </div>
+
+      <div className="flex-1 overflow-y-auto">
+        {subView === 'signals' && <SignalsView />}
+        {subView === 'patterns' && <PatternsView />}
+        {subView === 'proposals' && <ProposalsView />}
+      </div>
+    </div>
+  );
+}
+
+function SignalsView() {
+  const { data, isLoading } = useSignals(1, 20);
+  const collectMut = useCollectSignals();
+  const signals = data?.items ?? [];
+
+  return (
+    <div className="flex flex-col gap-2 p-3" data-testid="improvement-signals">
+      <div className="flex items-center justify-between">
+        <span className="text-xs text-secondary-400">{data?.total ?? 0} Signale</span>
+        <button
+          onClick={() => collectMut.mutate({ limit: 100 })}
+          disabled={collectMut.isPending}
+          className="inline-flex items-center gap-1 px-2 py-1 rounded text-xs font-medium text-primary-600 hover:bg-primary-50 disabled:opacity-50 min-h-touch"
+          aria-label="Signale sammeln"
+        >
+          <RefreshCw className={`w-3 h-3 ${collectMut.isPending ? 'animate-spin' : ''}`} aria-hidden="true" strokeWidth={2} />
+          Sammeln
+        </button>
+      </div>
+
+      {isLoading && <p className="text-sm text-secondary-400 text-center py-4">Laden...</p>}
+      {!isLoading && signals.length === 0 && (
+        <p className="text-sm text-secondary-400 text-center py-4">Keine Signale. Klicken Sie auf „Sammeln" um zu starten.</p>
+      )}
+
+      {signals.map(s => (
+        <div key={s.id} className="px-3 py-2 rounded-lg border border-secondary-200 bg-white hover:border-secondary-300 transition-colors">
+          <div className="flex items-center gap-2 mb-1">
+            <span className={`w-2 h-2 rounded-full flex-shrink-0 ${
+              s.severity === 'error' ? 'bg-danger-500' : s.severity === 'warning' ? 'bg-warning-500' : 'bg-secondary-300'
+            }`} aria-hidden="true" />
+            <span className="text-xs font-medium text-secondary-700 truncate">{s.source_type}</span>
+            <span className="text-xs text-secondary-400 ml-auto">{s.signal_kind}</span>
+          </div>
+          <p className="text-xs text-secondary-600 leading-snug">{s.summary}</p>
+          <div className="flex items-center gap-2 mt-1">
+            <span className="text-[10px] text-secondary-400">Confidence: {(s.confidence * 100).toFixed(0)}%</span>
+            {s.created_at && <span className="text-[10px] text-secondary-400 ml-auto">{new Date(s.created_at).toLocaleDateString()}</span>}
+          </div>
+        </div>
+      ))}
+    </div>
+  );
+}
+
+function PatternsView() {
+  const { data, isLoading } = usePatterns(1, 20);
+  const detectMut = useDetectPatterns();
+  const patterns = data?.items ?? [];
+
+  return (
+    <div className="flex flex-col gap-2 p-3" data-testid="improvement-patterns">
+      <div className="flex items-center justify-between">
+        <span className="text-xs text-secondary-400">{data?.total ?? 0} Muster</span>
+        <button
+          onClick={() => detectMut.mutate({ min_occurrences: 2 })}
+          disabled={detectMut.isPending}
+          className="inline-flex items-center gap-1 px-2 py-1 rounded text-xs font-medium text-primary-600 hover:bg-primary-50 disabled:opacity-50 min-h-touch"
+          aria-label="Muster erkennen"
+        >
+          <TrendingUp className={`w-3 h-3 ${detectMut.isPending ? 'animate-pulse' : ''}`} aria-hidden="true" strokeWidth={2} />
+          Erkennen
+        </button>
+      </div>
+
+      {isLoading && <p className="text-sm text-secondary-400 text-center py-4">Laden...</p>}
+      {!isLoading && patterns.length === 0 && (
+        <p className="text-sm text-secondary-400 text-center py-4">Keine Muster. Sammeln Sie zuerst Signale und klicken Sie dann auf „Erkennen".</p>
+      )}
+
+      {patterns.map(p => (
+        <div key={p.id} className="px-3 py-2 rounded-lg border border-secondary-200 bg-white hover:border-secondary-300 transition-colors">
+          <div className="flex items-center gap-2 mb-1">
+            <span className="text-xs font-semibold text-secondary-700 truncate flex-1">{p.title}</span>
+            <span className={`px-1.5 py-0.5 rounded text-[10px] font-medium ${
+              p.status === 'detected' ? 'bg-blue-100 text-blue-700' :
+              p.status === 'proposal_created' ? 'bg-purple-100 text-purple-700' :
+              p.status === 'resolved' ? 'bg-green-100 text-green-700' :
+              'bg-secondary-100 text-secondary-500'
+            }`}>{p.status}</span>
+          </div>
+          <p className="text-xs text-secondary-600 leading-snug mb-1">{p.description}</p>
+          <div className="flex items-center gap-2">
+            <span className="text-[10px] text-secondary-400">{p.occurrence_count}x</span>
+            <span className="text-[10px] text-secondary-400">Confidence: {(p.confidence * 100).toFixed(0)}%</span>
+            <span className="text-[10px] text-secondary-400 ml-auto">{p.target_type}</span>
+          </div>
+          {p.proposed_action && (
+            <p className="text-[11px] text-primary-600 mt-1 leading-snug">→ {p.proposed_action}</p>
+          )}
+        </div>
+      ))}
+    </div>
+  );
+}
+
+function ProposalsView() {
+  const { data, isLoading } = useProposals(1, 20);
+  const evalMut = useEvaluateProposal();
+  const activateMut = useActivateProposal();
+  const rollbackMut = useRollbackProposal();
+  const measureMut = useMeasureImpact();
+  const proposals = data?.items ?? [];
+
+  const statusColors: Record<string, string> = {
+    draft: 'bg-secondary-100 text-secondary-600',
+    evaluating: 'bg-yellow-100 text-yellow-700',
+    evaluated: 'bg-blue-100 text-blue-700',
+    pending_approval: 'bg-orange-100 text-orange-700',
+    approved: 'bg-green-100 text-green-700',
+    active: 'bg-emerald-100 text-emerald-700',
+    rolled_back: 'bg-red-100 text-red-700',
+    rejected: 'bg-danger-100 text-danger-700',
+    expired: 'bg-secondary-100 text-secondary-400',
+  };
+
+  return (
+    <div className="flex flex-col gap-2 p-3" data-testid="improvement-proposals">
+      <span className="text-xs text-secondary-400">{data?.total ?? 0} Vorschläge</span>
+
+      {isLoading && <p className="text-sm text-secondary-400 text-center py-4">Laden...</p>}
+      {!isLoading && proposals.length === 0 && (
+        <p className="text-sm text-secondary-400 text-center py-4">Keine Vorschläge.</p>
+      )}
+
+      {proposals.map(p => (
+        <div key={p.id} className="px-3 py-2 rounded-lg border border-secondary-200 bg-white hover:border-secondary-300 transition-colors">
+          <div className="flex items-center gap-2 mb-1">
+            <span className="text-xs font-semibold text-secondary-700 truncate flex-1">{p.title}</span>
+            <span className={`px-1.5 py-0.5 rounded text-[10px] font-medium ${statusColors[p.status] ?? statusColors.draft}`}>{p.status}</span>
+          </div>
+          <p className="text-xs text-secondary-600 leading-snug mb-1">{p.description}</p>
+          <div className="flex items-center gap-2 mb-2">
+            <span className="text-[10px] text-secondary-400">{p.target_type}</span>
+            {p.target_name && <span className="text-[10px] text-secondary-400">{p.target_name}</span>}
+            {p.evaluation_score > 0 && <span className="text-[10px] text-secondary-400">Score: {(p.evaluation_score * 100).toFixed(0)}%</span>}
+          </div>
+
+          {/* Action buttons based on status */}
+          <div className="flex gap-1 flex-wrap">
+            {(p.status === 'draft' || p.status === 'evaluated') && (
+              <button
+                onClick={() => evalMut.mutate(p.id)}
+                disabled={evalMut.isPending}
+                className="inline-flex items-center gap-1 px-2 py-1 rounded text-[11px] font-medium text-blue-600 hover:bg-blue-50 disabled:opacity-50 min-h-touch"
+                aria-label="Evaluieren"
+              >
+                <Play className="w-3 h-3" aria-hidden="true" strokeWidth={2} />
+                Evaluieren
+              </button>
+            )}
+            {(p.status === 'approved' || p.status === 'evaluated') && (
+              <button
+                onClick={() => activateMut.mutate(p.id)}
+                disabled={activateMut.isPending}
+                className="inline-flex items-center gap-1 px-2 py-1 rounded text-[11px] font-medium text-green-600 hover:bg-green-50 disabled:opacity-50 min-h-touch"
+                aria-label="Aktivieren"
+              >
+                <CheckCircle className="w-3 h-3" aria-hidden="true" strokeWidth={2} />
+                Aktivieren
+              </button>
+            )}
+            {p.status === 'active' && (
+              <>
+                <button
+                  onClick={() => rollbackMut.mutate({ proposalId: p.id, reason: 'Manual rollback' })}
+                  disabled={rollbackMut.isPending}
+                  className="inline-flex items-center gap-1 px-2 py-1 rounded text-[11px] font-medium text-danger-600 hover:bg-danger-50 disabled:opacity-50 min-h-touch"
+                  aria-label="Rollback"
+                >
+                  <RotateCcw className="w-3 h-3" aria-hidden="true" strokeWidth={2} />
+                  Rollback
+                </button>
+                <button
+                  onClick={() => measureMut.mutate(p.id)}
+                  disabled={measureMut.isPending}
+                  className="inline-flex items-center gap-1 px-2 py-1 rounded text-[11px] font-medium text-purple-600 hover:bg-purple-50 disabled:opacity-50 min-h-touch"
+                  aria-label="Impact messen"
+                >
+                  <BarChart3 className="w-3 h-3" aria-hidden="true" strokeWidth={2} />
+                  Messen
+                </button>
+              </>
+            )}
+          </div>
+        </div>
+      ))}
+    </div>
+  );
+}

frontend/src/components/layout/AISidebar.tsx

@@ -2,6 +2,7 @@ import React, { useState, useEffect } from 'react';
 import { ChatWindow } from '@/components/ai/ChatWindow';
 import { ResizablePanel } from '@/components/ui/ResizablePanel';
 import { SuggestionList } from '@/components/ai/SuggestionSidebar';
+import { ImprovementPanel } from '@/components/ai/ImprovementPanel';
 import { createSession, fetchSessions } from '@/api/ai';
 import { useUIStore } from '@/store/uiStore';
 import { useTranslation } from 'react-i18next';
@@ -172,7 +173,14 @@ export function AISidebar() {
 
   const renderTabContent = () => {
     if (aiSidebarTab === 'proactive') {
-      return <SuggestionList />;
+      return (
+        <div className="flex flex-col h-full">
+          <SuggestionList />
+          <div className="border-t border-secondary-200">
+            <ImprovementPanel />
+          </div>
+        </div>
+      );
     }
     if (aiSidebarTab === 'notifications') {
       return (