feat: regime system — Find Matching + By Regime view

- Pattern Lab: "Find Matching" button per pattern uses GPT-4o-mini to classify against library (merge_as_instance / counter_scenario / new_pattern); shows match badge + confidence + suggested #regime_tag; conditional action buttons (Merge / Save counter / Save new)
- save_pattern_from_run handles action='instance' (appends to historical_instances + updates stats), action='counter' (new pattern with counter_of link, tags parent regime_tag), action='new' (unchanged + regime_tag support)
- useApi.ts: extended useSaveLabPattern type + new useFindMatchingPattern mutation + MatchResult export type
- DB migrations: regime_tag + counter_of columns on custom_patterns
- PatternExplorer: new "By Regime" view groups saved patterns by regime_tag; RegimeCard shows historical instances, hit rate, counter-of link (orange); untagged group at bottom

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/hooks/useApi.ts

@@ -996,6 +996,8 @@ export const useSaveLabPattern = () => {
     mutationFn: (body: {
       run_id: string; pattern_index: number; name?: string;
       category?: string; signal_direction?: string; asset_class?: string;
+      action?: 'new' | 'instance' | 'counter';
+      target_id?: string; regime_tag?: string; event_name?: string;
     }) => api.post('/pattern-lab/save-pattern', body).then(r => r.data),
     onSuccess: () => {
       qc.invalidateQueries({ queryKey: ['all-patterns'] })
@@ -1004,6 +1006,21 @@ export const useSaveLabPattern = () => {
   })
 }
 
+export type MatchResult = {
+  recommendation: 'merge_as_instance' | 'counter_scenario' | 'new_pattern'
+  match_id?: string
+  match_name?: string
+  confidence: number
+  reasoning: string
+  suggested_regime_tag?: string
+}
+
+export const useFindMatchingPattern = () =>
+  useMutation({
+    mutationFn: (body: { run_id: string; pattern_index: number }): Promise<MatchResult> =>
+      api.post('/pattern-lab/find-matching', body).then(r => r.data),
+  })
+
 export const useDeleteLabRun = () => {
   const qc = useQueryClient()
   return useMutation({

frontend/src/pages/PatternExplorer.tsx

@@ -4,6 +4,7 @@ import clsx from 'clsx'
 import {
   TreePine, Search, ChevronRight, ChevronDown,
   TrendingUp, TrendingDown, Zap, BookOpen, ExternalLink, RefreshCw,
+  Layers, GitMerge, Tag,
 } from 'lucide-react'
 import {
   useAllPatterns,
@@ -58,6 +59,10 @@ interface Pattern {
   taxonomy_path?: string[]
   ai_quality_score?: number
   is_active?: number
+  regime_tag?: string
+  counter_of?: string
+  backtest_hits?: number
+  backtest_runs_count?: number
 }
 
 interface ScoreResult {
@@ -749,9 +754,136 @@ function InstrumentLens({ patterns }: { patterns: Pattern[] }) {
   )
 }
 
+// ── Regime View ───────────────────────────────────────────────────────────────
+
+function RegimeCard({ pattern, allPatterns }: { pattern: Pattern; allPatterns: Pattern[] }) {
+  const [open, setOpen] = useState(false)
+  const isCounter = !!pattern.counter_of
+  const counterOf = isCounter ? allPatterns.find(p => p.id === pattern.counter_of) : null
+  const instances = Array.isArray(pattern.historical_instances) ? pattern.historical_instances : []
+  const hitRate = pattern.backtest_runs_count
+    ? Math.round(((pattern.backtest_hits ?? 0) / pattern.backtest_runs_count) * 100)
+    : null
+
+  return (
+    <div className={clsx(
+      'border rounded-lg overflow-hidden transition-colors',
+      isCounter ? 'border-orange-700/50 bg-orange-900/5' : 'border-slate-700/50 bg-dark-700/30'
+    )}>
+      <button className="w-full flex items-center gap-3 p-3 text-left hover:bg-slate-800/30 transition-colors"
+        onClick={() => setOpen(v => !v)}>
+        {open ? <ChevronDown className="w-3.5 h-3.5 text-slate-500 shrink-0" /> : <ChevronRight className="w-3.5 h-3.5 text-slate-500 shrink-0" />}
+        {isCounter
+          ? <Layers className="w-4 h-4 text-orange-400 shrink-0" />
+          : <BookOpen className="w-4 h-4 text-violet-400 shrink-0" />}
+        <div className="flex-1 min-w-0">
+          <div className="flex items-center gap-2 flex-wrap">
+            <span className="text-sm font-semibold text-slate-100 truncate">{pattern.name}</span>
+            {isCounter && (
+              <span className="text-[10px] border border-orange-600 text-orange-400 rounded px-1.5 py-0.5 shrink-0">
+                counter of {counterOf?.name ?? pattern.counter_of}
+              </span>
+            )}
+            {pattern.signal_direction && (
+              <span className={clsx('text-[10px] rounded px-1.5 py-0.5 shrink-0',
+                pattern.signal_direction === 'up' ? 'bg-emerald-900/40 text-emerald-400' :
+                pattern.signal_direction === 'down' ? 'bg-red-900/40 text-red-400' : 'bg-slate-700 text-slate-400')}>
+                {pattern.signal_direction === 'up' ? '↑' : pattern.signal_direction === 'down' ? '↓' : '↕'} {pattern.signal_direction}
+              </span>
+            )}
+            {hitRate !== null && (
+              <span className={clsx('text-[10px] font-mono shrink-0',
+                hitRate >= 60 ? 'text-emerald-400' : hitRate >= 40 ? 'text-yellow-400' : 'text-red-400')}>
+                {hitRate}% ({pattern.backtest_hits}/{pattern.backtest_runs_count})
+              </span>
+            )}
+          </div>
+          <p className="text-[10px] text-slate-500 truncate mt-0.5">{pattern.description}</p>
+        </div>
+        <span className="text-[10px] text-slate-600 shrink-0 font-mono">{instances.length} events</span>
+      </button>
+      {open && instances.length > 0 && (
+        <div className="border-t border-slate-700/40 p-3 pt-2">
+          <div className="text-[10px] text-slate-500 mb-2 font-semibold uppercase tracking-wide">Historical instances</div>
+          <div className="flex flex-col gap-1.5">
+            {instances.map((inst: any, i: number) => (
+              <div key={i} className="flex items-center gap-3 text-[11px]">
+                <span className="text-slate-500 font-mono w-24 shrink-0">{inst.date ?? '—'}</span>
+                <span className="text-slate-300 flex-1 truncate">{inst.event_name ?? inst.event ?? inst.theme ?? '—'}</span>
+                {inst.hit !== undefined && (
+                  <span className={clsx('shrink-0', inst.hit_type === 'full' || inst.hit === true ? 'text-emerald-400' : inst.hit_type === 'partial' ? 'text-amber-400' : 'text-red-400')}>
+                    {inst.hit_type === 'full' || inst.hit === true ? '✓' : inst.hit_type === 'partial' ? '~' : '✗'}
+                  </span>
+                )}
+              </div>
+            ))}
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}
+
+function RegimeView({ patterns }: { patterns: Pattern[] }) {
+  const groups = useMemo(() => {
+    const byRegime: Record<string, Pattern[]> = {}
+    const untagged: Pattern[] = []
+    for (const p of patterns) {
+      if (p.source !== 'backtested' && p.source !== 'user') continue
+      if (p.regime_tag) {
+        ;(byRegime[p.regime_tag] ??= []).push(p)
+      } else {
+        untagged.push(p)
+      }
+    }
+    return { byRegime, untagged }
+  }, [patterns])
+
+  const regimes = Object.entries(groups.byRegime).sort((a, b) => b[1].length - a[1].length)
+
+  if (regimes.length === 0 && groups.untagged.length === 0) {
+    return (
+      <div className="flex flex-col items-center justify-center py-32 gap-3 text-slate-600">
+        <Tag className="w-8 h-8" />
+        <p className="text-sm">No saved patterns yet.</p>
+        <p className="text-xs">Use "Find Matching" in Pattern Lab to classify and save patterns into regimes.</p>
+      </div>
+    )
+  }
+
+  return (
+    <div className="flex flex-col gap-6">
+      {regimes.map(([tag, pats]) => (
+        <div key={tag} className="flex flex-col gap-2">
+          <div className="flex items-center gap-2">
+            <Tag className="w-3.5 h-3.5 text-violet-400" />
+            <span className="text-sm font-semibold text-violet-300">#{tag}</span>
+            <span className="text-xs text-slate-500">{pats.length} pattern{pats.length > 1 ? 's' : ''}</span>
+          </div>
+          <div className="flex flex-col gap-2 pl-4 border-l border-violet-900/40">
+            {pats.map(p => <RegimeCard key={p.id} pattern={p} allPatterns={patterns} />)}
+          </div>
+        </div>
+      ))}
+      {groups.untagged.length > 0 && (
+        <div className="flex flex-col gap-2">
+          <div className="flex items-center gap-2">
+            <Tag className="w-3.5 h-3.5 text-slate-500" />
+            <span className="text-sm font-semibold text-slate-500">Untagged</span>
+            <span className="text-xs text-slate-600">{groups.untagged.length} pattern{groups.untagged.length > 1 ? 's' : ''}</span>
+          </div>
+          <div className="flex flex-col gap-2 pl-4 border-l border-slate-700/40">
+            {groups.untagged.map(p => <RegimeCard key={p.id} pattern={p} allPatterns={patterns} />)}
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}
+
 // ── Page root ─────────────────────────────────────────────────────────────────
 
-type ViewMode = 'tree' | 'instrument'
+type ViewMode = 'tree' | 'instrument' | 'regime'
 
 export default function PatternExplorer() {
   const [view, setView] = useState<ViewMode>('tree')
@@ -810,6 +942,18 @@ export default function PatternExplorer() {
             <Search className="w-3.5 h-3.5" />
             Instrument
           </button>
+          <button
+            className={clsx(
+              'flex items-center gap-1.5 px-3 py-1.5 rounded text-sm font-medium transition-colors',
+              view === 'regime'
+                ? 'bg-violet-600/30 text-violet-300 border border-violet-500/30'
+                : 'text-slate-400 hover:text-slate-200'
+            )}
+            onClick={() => setView('regime')}
+          >
+            <Layers className="w-3.5 h-3.5" />
+            By Regime
+          </button>
         </div>
       </div>
 
@@ -823,6 +967,7 @@ export default function PatternExplorer() {
         <>
           {view === 'tree' && <TreeView patterns={patterns} />}
           {view === 'instrument' && <InstrumentLens patterns={patterns} />}
+          {view === 'regime' && <RegimeView patterns={patterns} />}
         </>
       )}
     </div>

frontend/src/pages/PatternLab.tsx

@@ -3,12 +3,14 @@ import {
   useRunPatternLab, useEvaluatePatternLab, useSaveLabPattern,
   usePatternLabRuns, useDeleteLabRun,
   useInstrumentScan, useEvaluateInstrumentScan,
+  useFindMatchingPattern, MatchResult,
   validateTicker,
 } from '../hooks/useApi'
 import {
   FlaskConical, Play, CheckCircle2, XCircle, MinusCircle,
   Trash2, Save, RefreshCw, Search, CalendarDays,
   TrendingUp, TrendingDown, Zap, BarChart2, ScanLine, DollarSign,
+  GitMerge, Layers, Plus,
 } from 'lucide-react'
 import clsx from 'clsx'
 import { INSTRUMENTS, INSTRUMENT_CATEGORIES } from '../constants/instruments'
@@ -255,6 +257,7 @@ export default function PatternLab() {
   const { mutate: deleteRun }                                  = useDeleteLabRun()
   const { mutateAsync: runInstScan,    isPending: scanning }   = useInstrumentScan()
   const { mutateAsync: evaluateInst,   isPending: evalInst }   = useEvaluateInstrumentScan()
+  const { mutateAsync: findMatching }                          = useFindMatchingPattern()
 
   const runs: any[] = runsData ?? []
 
@@ -283,9 +286,11 @@ export default function PatternLab() {
   const [instSavedIdx, setInstSavedIdx] = useState<Set<number>>(new Set())
 
   // ── Current run state (events mode)
-  const [activeRun, setActiveRun] = useState<any | null>(null)
-  const [savedIdx, setSavedIdx]   = useState<Set<number>>(new Set())
-  const [toast, setToast]         = useState<string | null>(null)
+  const [activeRun, setActiveRun]   = useState<any | null>(null)
+  const [savedIdx, setSavedIdx]     = useState<Set<number>>(new Set())
+  const [toast, setToast]           = useState<string | null>(null)
+  const [matchResults, setMatchResults] = useState<Record<string, MatchResult>>({})
+  const [matchLoading, setMatchLoading] = useState<Record<string, boolean>>({})
 
   const filteredPresets = useMemo(() => PRESETS.filter(p => {
     if (yearFilter && p.year !== yearFilter) return false
@@ -338,7 +343,28 @@ export default function PatternLab() {
     }
   }
 
-  const handleSave = async (idx: number) => {
+  const matchKey = (idx: number) => `${activeRun?.run_id}-${idx}`
+
+  const handleFindMatching = async (idx: number) => {
+    if (!activeRun?.run_id) return
+    const key = matchKey(idx)
+    setMatchLoading(prev => ({ ...prev, [key]: true }))
+    try {
+      const result = await findMatching({ run_id: activeRun.run_id, pattern_index: idx })
+      setMatchResults(prev => ({ ...prev, [key]: result }))
+    } catch (e: any) {
+      showToast(`Find matching failed: ${e?.response?.data?.detail ?? e?.message}`)
+    } finally {
+      setMatchLoading(prev => ({ ...prev, [key]: false }))
+    }
+  }
+
+  const handleSave = async (
+    idx: number,
+    action: 'new' | 'instance' | 'counter' = 'new',
+    target_id?: string,
+    regime_tag?: string,
+  ) => {
     if (!activeRun?.run_id) return
     const pat = activeRun.ai_result?.patterns?.[idx]
     if (!pat) return
@@ -349,9 +375,13 @@ export default function PatternLab() {
         name: pat.name,
         category: pat.category,
         signal_direction: pat.signal_direction,
+        action,
+        target_id,
+        regime_tag,
       })
       setSavedIdx(prev => new Set([...prev, idx]))
-      showToast(`"${pat.name}" saved to Pattern Library`)
+      const actionLabel = action === 'instance' ? 'merged as instance' : action === 'counter' ? 'saved as counter-scenario' : 'saved'
+      showToast(`"${pat.name}" ${actionLabel}`)
     } catch (e: any) {
       showToast(`Save failed: ${e?.response?.data?.detail ?? e?.message}`)
     }
@@ -853,18 +883,65 @@ export default function PatternLab() {
                             {out && <OutcomeRow out={out} />}
                           </div>
 
-                          {/* Save button */}
-                          <div className="flex-shrink-0">
+                          {/* Save / Find Matching buttons */}
+                          <div className="flex-shrink-0 flex flex-col items-end gap-2">
                             {isSaved ? (
                               <span className="flex items-center gap-1 text-emerald-400 text-xs">
                                 <CheckCircle2 className="w-3.5 h-3.5" /> Saved
                               </span>
-                            ) : (
-                              <button onClick={() => handleSave(idx)}
-                                className="flex items-center gap-1.5 border border-slate-600 hover:border-violet-500 hover:text-violet-300 text-slate-400 px-2.5 py-1.5 rounded text-xs transition-colors">
-                                <Save className="w-3 h-3" /> Save pattern
-                              </button>
-                            )}
+                            ) : (() => {
+                              const key = matchKey(idx)
+                              const mr = matchResults[key]
+                              const loading = matchLoading[key]
+                              if (mr) {
+                                const isInstance = mr.recommendation === 'merge_as_instance'
+                                const isCounter  = mr.recommendation === 'counter_scenario'
+                                const badgeColor = isInstance ? 'text-emerald-400 border-emerald-600' : isCounter ? 'text-orange-400 border-orange-600' : 'text-slate-400 border-slate-600'
+                                return (
+                                  <div className="flex flex-col items-end gap-1.5">
+                                    <div className={`text-[10px] border rounded px-1.5 py-0.5 ${badgeColor}`}>
+                                      {isInstance ? <><GitMerge className="w-3 h-3 inline mr-1" />Match: {mr.match_name} ({mr.confidence}%)</>
+                                       : isCounter ? <><Layers className="w-3 h-3 inline mr-1" />Counter of: {mr.match_name} ({mr.confidence}%)</>
+                                       : <><Plus className="w-3 h-3 inline mr-1" />New pattern</>}
+                                    </div>
+                                    {mr.suggested_regime_tag && (
+                                      <div className="text-[10px] text-violet-400 font-mono">#{mr.suggested_regime_tag}</div>
+                                    )}
+                                    <div className="flex gap-1.5">
+                                      {isInstance && mr.match_id && (
+                                        <button onClick={() => handleSave(idx, 'instance', mr.match_id, mr.suggested_regime_tag)}
+                                          className="flex items-center gap-1 border border-emerald-600 hover:border-emerald-400 text-emerald-400 px-2 py-1 rounded text-[10px] transition-colors">
+                                          <GitMerge className="w-3 h-3" /> Merge
+                                        </button>
+                                      )}
+                                      {isCounter && mr.match_id && (
+                                        <button onClick={() => handleSave(idx, 'counter', mr.match_id, mr.suggested_regime_tag)}
+                                          className="flex items-center gap-1 border border-orange-600 hover:border-orange-400 text-orange-400 px-2 py-1 rounded text-[10px] transition-colors">
+                                          <Layers className="w-3 h-3" /> Save counter
+                                        </button>
+                                      )}
+                                      <button onClick={() => handleSave(idx, 'new', undefined, mr.suggested_regime_tag)}
+                                        className="flex items-center gap-1 border border-slate-600 hover:border-slate-400 text-slate-400 px-2 py-1 rounded text-[10px] transition-colors">
+                                        <Save className="w-3 h-3" /> Save new
+                                      </button>
+                                    </div>
+                                  </div>
+                                )
+                              }
+                              return (
+                                <div className="flex gap-1.5">
+                                  <button onClick={() => handleFindMatching(idx)} disabled={loading}
+                                    className="flex items-center gap-1.5 border border-violet-700 hover:border-violet-400 text-violet-400 px-2.5 py-1.5 rounded text-xs transition-colors disabled:opacity-50">
+                                    {loading ? <RefreshCw className="w-3 h-3 animate-spin" /> : <GitMerge className="w-3 h-3" />}
+                                    Find matching
+                                  </button>
+                                  <button onClick={() => handleSave(idx)}
+                                    className="flex items-center gap-1.5 border border-slate-600 hover:border-violet-500 hover:text-violet-300 text-slate-400 px-2.5 py-1.5 rounded text-xs transition-colors">
+                                    <Save className="w-3 h-3" /> Save
+                                  </button>
+                                </div>
+                              )
+                            })()}
                           </div>
                         </div>
                       </div>