feat(ui): scope, freshness and jurist-review badges + live empty-state

Adds three dark-first chip badges in the TierBadge pattern:
- Jurisdiction (Berlin/DE/EU/International) — derived from the ELI,
  surfaced on the norms list, detail header and heatmap chips/hover.
- Freshness (aktuell/geaendert/ungeprueft) — flags norms amended
  upstream (standDate + sourceSha256); renders only when stale.
- Jurist review — marks evaluations a trusted jurist has confirmed
  (optional; the figure stands on its own).
Models gain Jurisdiction/Freshness enums, Norm.freshness/supersededNote
and Evaluation.reviewedBy/reviewedAt; HubRepository parses them from
the flow bag (ELI fallback). HeatmapPage shows a real empty-state
(hub-down vs no-evaluations) instead of a blank plot, and connect()
no longer throws on a failed probe.

Signed-off-by: flemming-it <sf@flemming.it>

app/lib/data/models.dart

@@ -51,6 +51,138 @@ extension EvidenceTierLabel on EvidenceTier {
       };
 }
 
+/// Geltungsbereich — the geographic/legal scope a norm belongs to.
+/// Nested by widening reach: Berlin ⊂ Deutschland ⊂ EU ⊂ Welt.
+/// Every norm carries one so the UI can flag, at a glance, *which*
+/// reform lever a figure speaks to (Bezirk/Senat, Bund, Brüssel,
+/// or völkerrechtlich) — see Studie §5.3.
+enum Jurisdiction {
+  /// Landesrecht Berlin (BauO Bln, ASOG, …) — Senat/Bezirk lever.
+  berlin,
+
+  /// Bundesrecht (GewO, MiLoG, KassenSichV) — NKR/Bundestag lever.
+  deutschland,
+
+  /// EU-Recht (DSGVO, REFIT) — Reform-Hebel liegt in Brüssel.
+  eu,
+
+  /// Völker-/Welthandelsrecht (WTO, OECD, UN) — international.
+  international,
+}
+
+extension JurisdictionLabel on Jurisdiction {
+  /// Kompakt-Code für Chips und enge Layouts.
+  String get short => switch (this) {
+        Jurisdiction.berlin => 'BE',
+        Jurisdiction.deutschland => 'DE',
+        Jurisdiction.eu => 'EU',
+        Jurisdiction.international => 'INT',
+      };
+
+  /// Voll ausgeschriebener Name.
+  String get label => switch (this) {
+        Jurisdiction.berlin => 'Berlin',
+        Jurisdiction.deutschland => 'Deutschland',
+        Jurisdiction.eu => 'EU',
+        Jurisdiction.international => 'International',
+      };
+
+  /// Rechtsebene — für Tooltip und Legend.
+  String get level => switch (this) {
+        Jurisdiction.berlin => 'Landesrecht Berlin',
+        Jurisdiction.deutschland => 'Bundesrecht',
+        Jurisdiction.eu => 'Recht der Europäischen Union',
+        Jurisdiction.international => 'Völker-/Welthandelsrecht',
+      };
+
+  /// Wo der Reform-Hebel ansetzt — die handlungsleitende Aussage.
+  String get reformLever => switch (this) {
+        Jurisdiction.berlin =>
+          'Reform-Hebel: Senat / Bezirk (Land Berlin)',
+        Jurisdiction.deutschland =>
+          'Reform-Hebel: Bundestag / NKR (Bund)',
+        Jurisdiction.eu =>
+          'Reform-Hebel: Brüssel — DE-Streichung allein wirkt nicht',
+        Jurisdiction.international =>
+          'Reform-Hebel: völkerrechtlich (WTO / OECD / UN)',
+      };
+
+  /// Ableitung aus der ELI/CELEX-Kennung, wenn kein Feld gesetzt
+  /// ist (Hub-Live-Modus liefert die ELI, nicht immer den Scope).
+  ///   eli/eu/…           → eu
+  ///   eli/land/be/…      → berlin
+  ///   eli/bund/…         → deutschland
+  ///   eli/int|un|wto/…   → international
+  static Jurisdiction fromEli(String eli) {
+    final e = eli.toLowerCase();
+    if (e.contains('/eu/') || e.startsWith('eli/eu') || e.contains('celex')) {
+      return Jurisdiction.eu;
+    }
+    if (e.contains('/land/be') || e.contains('/land/berlin') ||
+        e.contains('/be/')) {
+      return Jurisdiction.berlin;
+    }
+    if (e.contains('/int/') || e.contains('/un/') || e.contains('/wto/') ||
+        e.contains('/oecd/')) {
+      return Jurisdiction.international;
+    }
+    return Jurisdiction.deutschland;
+  }
+
+  /// Parse a serialized scope string from a hub flow bag, falling
+  /// back to ELI-derivation when absent or unrecognized.
+  static Jurisdiction parse(String? raw, {required String eli}) {
+    switch (raw?.trim().toLowerCase()) {
+      case 'berlin' || 'be' || 'land-berlin':
+        return Jurisdiction.berlin;
+      case 'deutschland' || 'de' || 'bund' || 'bundesrecht':
+        return Jurisdiction.deutschland;
+      case 'eu' || 'europa' || 'union':
+        return Jurisdiction.eu;
+      case 'international' || 'int' || 'welt' || 'global':
+        return Jurisdiction.international;
+      default:
+        return fromEli(eli);
+    }
+  }
+}
+
+/// Aktualität einer Norm-Fassung relativ zu unserer Datenbasis.
+/// Quelle der Wahrheit: `Norm.sourceSha256` gegen die aktuell
+/// veröffentlichte Quelle + `standDate`. Surfaced als Badge, damit
+/// eine veraltete Auswertung sofort erkennbar ist (Studie §5.3).
+enum Freshness {
+  /// Unsere Fassung == aktuell veröffentlichter Stand.
+  current,
+
+  /// Upstream geändert/aufgehoben — unsere Auswertung ist veraltet.
+  superseded,
+
+  /// Noch nicht gegen die Quelle abgeglichen.
+  unknown,
+}
+
+extension FreshnessLabel on Freshness {
+  String get label => switch (this) {
+        Freshness.current => 'aktuell',
+        Freshness.superseded => 'geändert',
+        Freshness.unknown => 'ungeprüft',
+      };
+
+  String get description => switch (this) {
+        Freshness.current =>
+          'Fassung entspricht dem aktuell veröffentlichten Stand.',
+        Freshness.superseded =>
+          'Quelle wurde upstream geändert — Auswertung veraltet, '
+              'Neubewertung nötig.',
+        Freshness.unknown =>
+          'Aktualität nicht gegen die Quelle abgeglichen.',
+      };
+
+  /// Stale-Zustände bekommen ein sichtbares Badge; `current` nicht.
+  bool get needsBadge => this != Freshness.current;
+}
+
 /// A citable source — never an LLM, always a public document or
 /// dataset reference. UI surfaces these next to every figure.
 class Source {
@@ -107,9 +239,12 @@ class Norm {
     required this.title,
     required this.jurabk,
     required this.paragraph,
+    required this.jurisdiction,
     required this.standDate,
     required this.sourceUrl,
     required this.sourceSha256,
+    this.freshness = Freshness.current,
+    this.supersededNote,
     this.paragraphs = const [],
   });
 
@@ -117,10 +252,23 @@ class Norm {
   final String title;
   final String jurabk;
   final String paragraph;
+
+  /// Geltungsbereich — Berlin / Deutschland / EU / International.
+  /// Surfaced as a scope badge wherever the norm appears.
+  final Jurisdiction jurisdiction;
+
   final DateTime standDate;
   final String sourceUrl;
   final String sourceSha256;
 
+  /// Aktualität dieser Fassung gegenüber der Quelle.
+  final Freshness freshness;
+
+  /// Optionaler Klartext-Hinweis, *was* sich geändert hat (z. B.
+  /// "BEG IV hat §17 zum 1.1.2026 entschärft"). Nur gesetzt, wenn
+  /// freshness != current.
+  final String? supersededNote;
+
   /// The actual paragraphs of the norm text, normalised by
   /// `text.akoma_normalize` in live mode. In demo mode the
   /// fixture quotes the public source verbatim under §5 UrhG
@@ -143,6 +291,8 @@ class Evaluation {
     required this.auditEventId,
     this.notes,
     this.componentSummary = const [],
+    this.reviewedBy,
+    this.reviewedAt,
   });
 
   final Norm norm;
@@ -179,4 +329,15 @@ class Evaluation {
   /// extras — each carries its tier-tag inline. Empty list ⇒
   /// fall back to the notes field for the list view.
   final List<String> componentSummary;
+
+  /// Jurist who confirmed this evaluation (the `by` of the hub
+  /// approval). Null ⇒ not yet reviewed. Jurist review is OPTIONAL:
+  /// the figure stands on its own; a review only *confirms* it.
+  final String? reviewedBy;
+
+  /// When the jurist signed off. Null ⇒ not reviewed.
+  final DateTime? reviewedAt;
+
+  /// True once a trusted jurist has confirmed this evaluation.
+  bool get isReviewed => reviewedBy != null;
 }