fix(welcome): concept cards speak everyday language first

The Hub/Module/Flow cards explained the basics in the very
vocabulary they were supposed to introduce (Rust binary, WASM,
YAML, hash-chained). Each card now leads with a plain-language
explanation; the technical wording moved behind a per-card
'for the technically curious' toggle. DE and EN.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/l10n/app_de.arb

@@ -22,11 +22,15 @@
   "welcomeHeroTitle": "Ch∆In Platform",
   "welcomeHeroSubtitle": "Deterministische Workflow-Engine für KI-gestützte Datenverarbeitung in regulierten Umgebungen.",
   "welcomePillarHubTitle": "Hub",
-  "welcomePillarHubBody": "Ein Rust-Binary, das Module lädt und Flows ausführt. SQLite für den State. Kein Docker, kein Message-Broker, keine Hintergrunddienste, die gepflegt werden müssen.",
+  "welcomePillarHubBody": "Das Programm, das alles ausführt. Es läuft direkt auf Ihrem Rechner, braucht keine Zusatzsoftware und speichert alles Wichtige in einer einzigen Datei.",
+  "welcomePillarHubTech": "Ein Rust-Binary, das Module lädt und Flows ausführt. SQLite für den Zustand. Kein Docker, kein Message-Broker, keine Hintergrunddienste, die gepflegt werden müssen.",
   "welcomePillarModuleTitle": "Modul",
-  "welcomePillarModuleBody": "Eine kleine WebAssembly-Komponente, die eine Sache macht. Deklariert Netzwerk-Endpunkte, Dateien und Umgebungsvariablen, auf die sie zugreift; der Hub setzt die Liste durch.",
+  "welcomePillarModuleBody": "Ein Baustein, der genau eine Aufgabe erledigt — zum Beispiel Text aus Dokumenten lesen. Jedes Modul sagt vorab, worauf es zugreifen will; mehr erlaubt der Hub nicht.",
+  "welcomePillarModuleTech": "Eine kleine WebAssembly-Komponente in einer Sandbox. Deklariert Netzwerk-Endpunkte, Dateien und Umgebungsvariablen, auf die sie zugreift; der Hub setzt die Liste durch.",
   "welcomePillarFlowTitle": "Flow",
-  "welcomePillarFlowBody": "Eine YAML-Datei, die Module verkettet. Eingaben rein, Module laufen in der deklarierten Reihenfolge, Ausgaben raus — jeder Schritt in einem hash-verketteten Audit-Log festgehalten.",
+  "welcomePillarFlowBody": "Ein Ablaufplan, der Module zu festen Schritten verbindet. Eingaben rein, Schritte laufen der Reihe nach, Ergebnis raus — und jeder Schritt wird fälschungssicher protokolliert.",
+  "welcomePillarFlowTech": "Eine YAML-Datei, die Module verkettet; jeder Schritt wird in einem hash-verketteten Audit-Log festgehalten, das die Diagnose-Seite komplett verifiziert.",
+  "welcomePillarTechToggle": "Für Technik-Interessierte",
   "welcomeTrustHeader": "TRUST-POSTURE",
   "welcomeTrustSandboxTitle": "Sandbox von Anfang an",
   "welcomeTrustSandboxBody": "Jedes Modul bringt eine explizite Berechtigungsliste mit — Netzwerk-Endpunkte, Dateien, Umgebungsvariablen. Der Hub setzt sie durch; ohne Operator-Freigabe verlässt nichts die Sandbox.",

lib/l10n/app_en.arb

@@ -30,11 +30,15 @@
   "welcomeHeroTitle": "Ch∆In Platform",
   "welcomeHeroSubtitle": "Deterministic workflow engine for AI-assisted data processing in regulated environments.",
   "welcomePillarHubTitle": "Hub",
-  "welcomePillarHubBody": "One Rust binary that loads modules and runs flows. SQLite for state. No Docker, no message broker, no background services to babysit.",
+  "welcomePillarHubBody": "The program that runs everything. It works right on your machine, needs no extra software, and keeps everything important in a single file.",
+  "welcomePillarHubTech": "One Rust binary that loads modules and runs flows. SQLite for state. No Docker, no message broker, no background services to babysit.",
   "welcomePillarModuleTitle": "Module",
-  "welcomePillarModuleBody": "A small WebAssembly component that does one thing. Declares the network endpoints, files, and environment variables it touches; the hub enforces the list.",
+  "welcomePillarModuleBody": "A building block that does exactly one job — reading text out of documents, say. Every module states up front what it wants to touch; the hub allows nothing more.",
+  "welcomePillarModuleTech": "A small, sandboxed WebAssembly component. Declares the network endpoints, files, and environment variables it touches; the hub enforces the list.",
   "welcomePillarFlowTitle": "Flow",
-  "welcomePillarFlowBody": "A YAML file that chains modules together. Inputs go in, modules run in declared order, outputs come out — every step recorded in a hash-chained audit log.",
+  "welcomePillarFlowBody": "A recipe that connects modules into fixed steps. Inputs go in, steps run in order, the result comes out — and every step is recorded tamper-evidently.",
+  "welcomePillarFlowTech": "A YAML file that chains modules together; every step is recorded in a hash-chained audit log that the Diagnostics page verifies in full.",
+  "welcomePillarTechToggle": "For the technically curious",
   "welcomeTrustHeader": "TRUST POSTURE",
   "welcomeTrustSandboxTitle": "Sandbox by default",
   "welcomeTrustSandboxBody": "Every module ships with an explicit permission list — network endpoints, files, environment variables. The hub enforces it; nothing reaches outside the sandbox without operator approval.",

lib/l10n/app_localizations.dart

@@ -233,9 +233,15 @@ abstract class AppLocalizations {
   /// No description provided for @welcomePillarHubBody.
   ///
   /// In en, this message translates to:
-  /// **'One Rust binary that loads modules and runs flows. SQLite for state. No Docker, no message broker, no background services to babysit.'**
+  /// **'The program that runs everything. It works right on your machine, needs no extra software, and keeps everything important in a single file.'**
   String get welcomePillarHubBody;
 
+  /// No description provided for @welcomePillarHubTech.
+  ///
+  /// In en, this message translates to:
+  /// **'One Rust binary that loads modules and runs flows. SQLite for state. No Docker, no message broker, no background services to babysit.'**
+  String get welcomePillarHubTech;
+
   /// No description provided for @welcomePillarModuleTitle.
   ///
   /// In en, this message translates to:
@@ -245,9 +251,15 @@ abstract class AppLocalizations {
   /// No description provided for @welcomePillarModuleBody.
   ///
   /// In en, this message translates to:
-  /// **'A small WebAssembly component that does one thing. Declares the network endpoints, files, and environment variables it touches; the hub enforces the list.'**
+  /// **'A building block that does exactly one job — reading text out of documents, say. Every module states up front what it wants to touch; the hub allows nothing more.'**
   String get welcomePillarModuleBody;
 
+  /// No description provided for @welcomePillarModuleTech.
+  ///
+  /// In en, this message translates to:
+  /// **'A small, sandboxed WebAssembly component. Declares the network endpoints, files, and environment variables it touches; the hub enforces the list.'**
+  String get welcomePillarModuleTech;
+
   /// No description provided for @welcomePillarFlowTitle.
   ///
   /// In en, this message translates to:
@@ -257,9 +269,21 @@ abstract class AppLocalizations {
   /// No description provided for @welcomePillarFlowBody.
   ///
   /// In en, this message translates to:
-  /// **'A YAML file that chains modules together. Inputs go in, modules run in declared order, outputs come out — every step recorded in a hash-chained audit log.'**
+  /// **'A recipe that connects modules into fixed steps. Inputs go in, steps run in order, the result comes out — and every step is recorded tamper-evidently.'**
   String get welcomePillarFlowBody;
 
+  /// No description provided for @welcomePillarFlowTech.
+  ///
+  /// In en, this message translates to:
+  /// **'A YAML file that chains modules together; every step is recorded in a hash-chained audit log that the Diagnostics page verifies in full.'**
+  String get welcomePillarFlowTech;
+
+  /// No description provided for @welcomePillarTechToggle.
+  ///
+  /// In en, this message translates to:
+  /// **'For the technically curious'**
+  String get welcomePillarTechToggle;
+
   /// No description provided for @welcomeTrustHeader.
   ///
   /// In en, this message translates to:
@@ -5056,15 +5080,21 @@ abstract class AppLocalizations {
   /// No description provided for @runsEmptyTitle.
   ///
   /// In en, this message translates to:
-  /// **'No detached runs'**
+  /// **'No background runs'**
   String get runsEmptyTitle;
 
   /// No description provided for @runsEmptyHint.
   ///
   /// In en, this message translates to:
-  /// **'Runs submitted with detach stay here until they finish. Detached invocations are opt-in — enable detached.enabled in the operator config to use them.'**
+  /// **'Runs that keep working in the background while you do something else appear here. The feature is optional and off by default — the guide shows step by step how to turn it on.'**
   String get runsEmptyHint;
 
+  /// No description provided for @runsEmptyGuideButton.
+  ///
+  /// In en, this message translates to:
+  /// **'Open the guide'**
+  String get runsEmptyGuideButton;
+
   /// No description provided for @runsCancelButton.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -83,21 +83,36 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get welcomePillarHubBody =>
-      'Ein Rust-Binary, das Module lädt und Flows ausführt. SQLite für den State. Kein Docker, kein Message-Broker, keine Hintergrunddienste, die gepflegt werden müssen.';
+      'Das Programm, das alles ausführt. Es läuft direkt auf Ihrem Rechner, braucht keine Zusatzsoftware und speichert alles Wichtige in einer einzigen Datei.';
+
+  @override
+  String get welcomePillarHubTech =>
+      'Ein Rust-Binary, das Module lädt und Flows ausführt. SQLite für den Zustand. Kein Docker, kein Message-Broker, keine Hintergrunddienste, die gepflegt werden müssen.';
 
   @override
   String get welcomePillarModuleTitle => 'Modul';
 
   @override
   String get welcomePillarModuleBody =>
-      'Eine kleine WebAssembly-Komponente, die eine Sache macht. Deklariert Netzwerk-Endpunkte, Dateien und Umgebungsvariablen, auf die sie zugreift; der Hub setzt die Liste durch.';
+      'Ein Baustein, der genau eine Aufgabe erledigt — zum Beispiel Text aus Dokumenten lesen. Jedes Modul sagt vorab, worauf es zugreifen will; mehr erlaubt der Hub nicht.';
+
+  @override
+  String get welcomePillarModuleTech =>
+      'Eine kleine WebAssembly-Komponente in einer Sandbox. Deklariert Netzwerk-Endpunkte, Dateien und Umgebungsvariablen, auf die sie zugreift; der Hub setzt die Liste durch.';
 
   @override
   String get welcomePillarFlowTitle => 'Flow';
 
   @override
   String get welcomePillarFlowBody =>
-      'Eine YAML-Datei, die Module verkettet. Eingaben rein, Module laufen in der deklarierten Reihenfolge, Ausgaben raus — jeder Schritt in einem hash-verketteten Audit-Log festgehalten.';
+      'Ein Ablaufplan, der Module zu festen Schritten verbindet. Eingaben rein, Schritte laufen der Reihe nach, Ergebnis raus — und jeder Schritt wird fälschungssicher protokolliert.';
+
+  @override
+  String get welcomePillarFlowTech =>
+      'Eine YAML-Datei, die Module verkettet; jeder Schritt wird in einem hash-verketteten Audit-Log festgehalten, das die Diagnose-Seite komplett verifiziert.';
+
+  @override
+  String get welcomePillarTechToggle => 'Für Technik-Interessierte';
 
   @override
   String get welcomeTrustHeader => 'TRUST-POSTURE';
@@ -2980,11 +2995,14 @@ class AppLocalizationsDe extends AppLocalizations {
   String get runsReloadTooltip => 'Lauf-Liste neu laden';
 
   @override
-  String get runsEmptyTitle => 'Keine abgekoppelten Läufe';
+  String get runsEmptyTitle => 'Keine Läufe im Hintergrund';
 
   @override
   String get runsEmptyHint =>
-      'Mit detach gestartete Läufe stehen hier, bis sie fertig sind. Abgekoppelte Aufrufe sind optional — dazu detached.enabled in der Betreiber-Konfiguration aktivieren.';
+      'Hier erscheinen Läufe, die im Hintergrund weiterlaufen, während Sie anderes tun. Diese Funktion ist optional und standardmäßig ausgeschaltet — die Anleitung zeigt Schritt für Schritt, wie sie eingeschaltet wird.';
+
+  @override
+  String get runsEmptyGuideButton => 'Anleitung öffnen';
 
   @override
   String get runsCancelButton => 'Abbrechen';

lib/l10n/app_localizations_en.dart

@@ -84,6 +84,10 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get welcomePillarHubBody =>
+      'The program that runs everything. It works right on your machine, needs no extra software, and keeps everything important in a single file.';
+
+  @override
+  String get welcomePillarHubTech =>
       'One Rust binary that loads modules and runs flows. SQLite for state. No Docker, no message broker, no background services to babysit.';
 
   @override
@@ -91,14 +95,25 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get welcomePillarModuleBody =>
-      'A small WebAssembly component that does one thing. Declares the network endpoints, files, and environment variables it touches; the hub enforces the list.';
+      'A building block that does exactly one job — reading text out of documents, say. Every module states up front what it wants to touch; the hub allows nothing more.';
+
+  @override
+  String get welcomePillarModuleTech =>
+      'A small, sandboxed WebAssembly component. Declares the network endpoints, files, and environment variables it touches; the hub enforces the list.';
 
   @override
   String get welcomePillarFlowTitle => 'Flow';
 
   @override
   String get welcomePillarFlowBody =>
-      'A YAML file that chains modules together. Inputs go in, modules run in declared order, outputs come out — every step recorded in a hash-chained audit log.';
+      'A recipe that connects modules into fixed steps. Inputs go in, steps run in order, the result comes out — and every step is recorded tamper-evidently.';
+
+  @override
+  String get welcomePillarFlowTech =>
+      'A YAML file that chains modules together; every step is recorded in a hash-chained audit log that the Diagnostics page verifies in full.';
+
+  @override
+  String get welcomePillarTechToggle => 'For the technically curious';
 
   @override
   String get welcomeTrustHeader => 'TRUST POSTURE';
@@ -2981,11 +2996,14 @@ class AppLocalizationsEn extends AppLocalizations {
   String get runsReloadTooltip => 'Reload the runs list';
 
   @override
-  String get runsEmptyTitle => 'No detached runs';
+  String get runsEmptyTitle => 'No background runs';
 
   @override
   String get runsEmptyHint =>
-      'Runs submitted with detach stay here until they finish. Detached invocations are opt-in — enable detached.enabled in the operator config to use them.';
+      'Runs that keep working in the background while you do something else appear here. The feature is optional and off by default — the guide shows step by step how to turn it on.';
+
+  @override
+  String get runsEmptyGuideButton => 'Open the guide';
 
   @override
   String get runsCancelButton => 'Cancel';

lib/pages/welcome.dart

@@ -310,17 +310,24 @@ class _PillarRow extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final l = AppLocalizations.of(context)!;
-    final pillars = <(IconData, String, String)>[
+    final pillars = <(IconData, String, String, String)>[
-      (Icons.hub_outlined, l.welcomePillarHubTitle, l.welcomePillarHubBody),
+      (
+        Icons.hub_outlined,
+        l.welcomePillarHubTitle,
+        l.welcomePillarHubBody,
+        l.welcomePillarHubTech,
+      ),
       (
         Icons.extension_outlined,
         l.welcomePillarModuleTitle,
         l.welcomePillarModuleBody,
+        l.welcomePillarModuleTech,
       ),
       (
         Icons.account_tree_outlined,
         l.welcomePillarFlowTitle,
         l.welcomePillarFlowBody,
+        l.welcomePillarFlowTech,
       ),
     ];
     return LayoutBuilder(
@@ -333,7 +340,7 @@ class _PillarRow extends StatelessWidget {
           return Column(
             children: [
               for (final p in pillars) ...[
-                _Pillar(icon: p.$1, title: p.$2, body: p.$3),
+                _Pillar(icon: p.$1, title: p.$2, body: p.$3, tech: p.$4),
                 const SizedBox(height: ChainSpace.md),
               ],
             ],
@@ -356,6 +363,7 @@ class _PillarRow extends StatelessWidget {
                     icon: pillars[i].$1,
                     title: pillars[i].$2,
                     body: pillars[i].$3,
+                    tech: pillars[i].$4,
                   ),
                 ),
               ],
@@ -367,16 +375,34 @@ class _PillarRow extends StatelessWidget {
   }
 }
 
-class _Pillar extends StatelessWidget {
+/// Concept card in everyday language; the technical wording
+/// (Rust, WASM, YAML, hash chain) lives behind a per-card
+/// "for the technically curious" toggle so the first read
+/// never requires developer vocabulary.
+class _Pillar extends StatefulWidget {
   final IconData icon;
   final String title;
   final String body;
+  final String tech;
 
-  const _Pillar({required this.icon, required this.title, required this.body});
+  const _Pillar({
+    required this.icon,
+    required this.title,
+    required this.body,
+    required this.tech,
+  });
+
+  @override
+  State<_Pillar> createState() => _PillarState();
+}
+
+class _PillarState extends State<_Pillar> {
+  bool _techOpen = false;
 
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
+    final l = AppLocalizations.of(context)!;
     return Container(
       padding: const EdgeInsets.all(ChainSpace.lg),
       decoration: BoxDecoration(
@@ -387,22 +413,57 @@ class _Pillar extends StatelessWidget {
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
-          Icon(icon, size: 28, color: theme.colorScheme.primary),
+          Icon(widget.icon, size: 28, color: theme.colorScheme.primary),
           const SizedBox(height: ChainSpace.md),
           Text(
-            title,
+            widget.title,
             style: theme.textTheme.titleLarge?.copyWith(
               fontWeight: FontWeight.w700,
             ),
           ),
           const SizedBox(height: ChainSpace.sm),
           Text(
-            body,
+            widget.body,
             style: theme.textTheme.bodyMedium?.copyWith(
               color: theme.colorScheme.onSurfaceVariant,
               height: 1.45,
             ),
           ),
+          const SizedBox(height: ChainSpace.sm),
+          InkWell(
+            onTap: () => setState(() => _techOpen = !_techOpen),
+            borderRadius: BorderRadius.circular(ChainRadius.sm),
+            child: Padding(
+              padding: const EdgeInsets.symmetric(vertical: 2),
+              child: Row(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Icon(
+                    _techOpen ? Icons.expand_less : Icons.expand_more,
+                    size: 16,
+                    color: theme.colorScheme.primary,
+                  ),
+                  const SizedBox(width: 4),
+                  Text(
+                    l.welcomePillarTechToggle,
+                    style: theme.textTheme.labelMedium?.copyWith(
+                      color: theme.colorScheme.primary,
+                    ),
+                  ),
+                ],
+              ),
+            ),
+          ),
+          if (_techOpen) ...[
+            const SizedBox(height: ChainSpace.xs),
+            Text(
+              widget.tech,
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: theme.colorScheme.onSurfaceVariant,
+                height: 1.45,
+              ),
+            ),
+          ],
         ],
       ),
     );