feat(ui): inline the normative text + open-source URL

Adds the actual paragraphs of the law right next to the
evaluation panel on the norm-detail page. A reviewer no longer
has to leave the app to confirm what a score is about; the
canonical source URL stays one click away via 'Im Browser
öffnen' (url_launcher) and one click away as a clipboard copy.

Schema

  models.dart gains a NormParagraph (number + text). Norm carries
  a List<NormParagraph> paragraphs, defaulted to const [] so
  norms harvested by text.akoma_normalize@^0 in live mode slot
  in without breaking the Mock path.

Demo data

  fixtures.dart embeds the public source paragraphs verbatim
  under §5 UrhG (amtliche Werke) for the five pilot norms.

Plumbing

  NormTextCard (lib/widgets/norm_text_card.dart) is the renderer:
  per-paragraph hanging label, selectable body text, source URL
  in mono at the bottom, two action buttons. NormDetailPage
  drops the card between the metric row and the duties card so
  the eye lands on it during a 'why this score?' read-through.

macOS sandbox

  The Release entitlement file gains
  com.apple.security.network.client so url_launcher's NSWorkspace
  call and the HubRepository's gRPC channel can both reach the
  network. The DebugProfile already had server; client matches
  the production posture.

  GeneratedPluginRegistrant.swift was re-generated by
  flutter pub get after url_launcher was added — no hand edits.

flutter analyze: clean. flutter test: 2/2 passing. The macOS
build via build-macos.sh launches and the new card renders the
GewO § 14, KassenSichV, DSGVO Art. 30, BauO Bln § 60 ff and
MiLoG § 17 fixtures with their actual normative text.

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

app/macos/Flutter/GeneratedPluginRegistrant.swift

@@ -6,7 +6,9 @@ import FlutterMacOS
 import Foundation
 
 import shared_preferences_foundation
+import url_launcher_macos
 
 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   SharedPreferencesPlugin.register(with: registry.registrar(forPlugin: "SharedPreferencesPlugin"))
+  UrlLauncherPlugin.register(with: registry.registrar(forPlugin: "UrlLauncherPlugin"))
 }