feat(dashboard): LLM stats answer who/what spends tokens — member scope chips and spend breakdowns

The stats section was designed single-user: four global charts, no
attribution. Request metadata rows now carry the session's source and
the frame's agent_id/depth (additive ensure_column), denormalized at log
time by the LoggingModel from the owner's pool — off the turn's hot
path, degrading to NULLs, never to a lost row.

The dashboard gains member scope chips filtering every chart, and a
breakdown row splitting the range's billed tokens by member, kind
(chat / sub-agents / cron / system agents / channels), agent, model and
provider — a sub-agent's spend is attributed to the sub-agent itself.
Rows predating the columns group under 'older data'.

web/i18n/en.js

@@ -419,7 +419,6 @@ export default {
   'dashboard.stats.requests': 'Requests {per}',
   'dashboard.stats.tokens':   'Tokens {per}',
   'dashboard.stats.latency':  'Avg latency (ms)',
-  'dashboard.stats.models':   'Models',
   'dashboard.stats.per_min':  '/ min',
   'dashboard.stats.per_hour': '/ hour',
   'dashboard.stats.per_day':  '/ day',
@@ -435,6 +434,26 @@ export default {
   'dashboard.stats.chart.non_cached': 'Non-cached',
   'dashboard.stats.chart.cache_hit':  'Cache hit: {pct}%',
 
+  'dashboard.stats.scope.all':      'Everyone',
+  'dashboard.stats.sub.breakdown':  'How the spend splits in the selected range',
+  'dashboard.stats.by_user':        'By member',
+  'dashboard.stats.by_kind':        'By kind',
+  'dashboard.stats.by_agent':       'By agent',
+  'dashboard.stats.by_model':       'By model',
+  'dashboard.stats.by_provider':    'By provider',
+  'dashboard.stats.user_unknown':   'Unknown',
+  'dashboard.stats.tip.requests':   'requests',
+
+  'dashboard.stats.kind.web':                 'Chat',
+  'dashboard.stats.kind.mobile':              'Mobile',
+  'dashboard.stats.kind.telegram':            'Telegram',
+  'dashboard.stats.kind.cron':                'Scheduled tasks',
+  'dashboard.stats.kind.sub_agent':           'Sub-agents',
+  'dashboard.stats.kind.event_triage':        'Event triage',
+  'dashboard.stats.kind.memory_lint':         'Memory lint',
+  'dashboard.stats.kind.conversation_review': 'Conversation review',
+  'dashboard.stats.kind.unknown':             'Older data',
+
   'dashboard.hero.subtitle':  'Your AI command centre — research, code, plan, and orchestrate. All in one place.',
 
   'dashboard.banner.no_models.title':  'No LLM models configured.',

web/i18n/fr.js

@@ -416,7 +416,6 @@ export default {
   'dashboard.stats.requests': 'Requêtes {per}',
   'dashboard.stats.tokens':   'Tokens {per}',
   'dashboard.stats.latency':  'Latence moyenne (ms)',
-  'dashboard.stats.models':   'Modèles',
   'dashboard.stats.per_min':  '/ min',
   'dashboard.stats.per_hour': '/ heure',
   'dashboard.stats.per_day':  '/ jour',
@@ -432,6 +431,26 @@ export default {
   'dashboard.stats.chart.non_cached': 'Non en cache',
   'dashboard.stats.chart.cache_hit':  'Cache hit : {pct}%',
 
+  'dashboard.stats.scope.all':      'Tous',
+  'dashboard.stats.sub.breakdown':  'Répartition des dépenses sur la période sélectionnée',
+  'dashboard.stats.by_user':        'Par membre',
+  'dashboard.stats.by_kind':        'Par type',
+  'dashboard.stats.by_agent':       'Par agent',
+  'dashboard.stats.by_model':       'Par modèle',
+  'dashboard.stats.by_provider':    'Par fournisseur',
+  'dashboard.stats.user_unknown':   'Inconnu',
+  'dashboard.stats.tip.requests':   'requêtes',
+
+  'dashboard.stats.kind.web':                 'Chat',
+  'dashboard.stats.kind.mobile':              'Mobile',
+  'dashboard.stats.kind.telegram':            'Telegram',
+  'dashboard.stats.kind.cron':                'Tâches planifiées',
+  'dashboard.stats.kind.sub_agent':           'Sous-agents',
+  'dashboard.stats.kind.event_triage':        'Triage des événements',
+  'dashboard.stats.kind.memory_lint':         'Lint mémoire',
+  'dashboard.stats.kind.conversation_review': 'Revue des conversations',
+  'dashboard.stats.kind.unknown':             'Données anciennes',
+
   'dashboard.hero.subtitle':  'Votre centre de commande IA — recherche, code, planification et orchestration. Tout en un seul endroit.',
 
   'dashboard.banner.no_models.title':  'Aucun modèle LLM configuré.',

web/i18n/it.js

@@ -416,7 +416,6 @@ export default {
   'dashboard.stats.requests': 'Richieste {per}',
   'dashboard.stats.tokens':   'Token {per}',
   'dashboard.stats.latency':  'Latenza media (ms)',
-  'dashboard.stats.models':   'Modelli',
   'dashboard.stats.per_min':  '/ min',
   'dashboard.stats.per_hour': '/ h',
   'dashboard.stats.per_day':  '/ giorno',
@@ -432,6 +431,26 @@ export default {
   'dashboard.stats.chart.non_cached': 'Non in cache',
   'dashboard.stats.chart.cache_hit':  'Cache hit: {pct}%',
 
+  'dashboard.stats.scope.all':      'Tutti',
+  'dashboard.stats.sub.breakdown':  'Come si distribuisce la spesa nel periodo selezionato',
+  'dashboard.stats.by_user':        'Per membro',
+  'dashboard.stats.by_kind':        'Per tipo',
+  'dashboard.stats.by_agent':       'Per agente',
+  'dashboard.stats.by_model':       'Per modello',
+  'dashboard.stats.by_provider':    'Per provider',
+  'dashboard.stats.user_unknown':   'Sconosciuto',
+  'dashboard.stats.tip.requests':   'richieste',
+
+  'dashboard.stats.kind.web':                 'Chat',
+  'dashboard.stats.kind.mobile':              'Mobile',
+  'dashboard.stats.kind.telegram':            'Telegram',
+  'dashboard.stats.kind.cron':                'Attività pianificate',
+  'dashboard.stats.kind.sub_agent':           'Sub-agent',
+  'dashboard.stats.kind.event_triage':        'Triage eventi',
+  'dashboard.stats.kind.memory_lint':         'Lint memoria',
+  'dashboard.stats.kind.conversation_review': 'Revisione conversazioni',
+  'dashboard.stats.kind.unknown':             'Dati precedenti',
+
   'dashboard.hero.subtitle':  'Il tuo centro di comando AI — ricerca, codice, pianificazione e orchestrazione. Tutto in un unico posto.',
 
   'dashboard.banner.no_models.title':  'Nessun modello LLM configurato.',