fix(approvals,l10n,theme): usertest findings — localized prompts, no-data confirm, .chain log path, honest wording, AA contrast

- approvals: empty/legacy hub prompts render the localized fallback;
  approving without show: data asks for conscious confirmation first
- chain_log: write to ~/.chain/logs/studio-errors.log (was .fai),
  one-time best-effort migration of the legacy file + rotation sibling
- l10n: 'manipulationssicher' -> 'manipulationserkennend', neutral
  WORM-1 blurb, doctor pill 'Integritätskette v1', federation hint
  says the CA authenticates the first connect (DE+EN)
- theme: muted text token now >=4.5:1 on canvas, cards and elevated
  dark surfaces (was 3.7:1 on cards)

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

CHANGELOG.md

@@ -5,6 +5,31 @@ version + `kStudioVersion` in `lib/main.dart` stay in lockstep.
 
 ## Unreleased
 
+### Fixed (usertest 2026-07-10 findings)
+
+- **Approval prompts localize.** An approval whose flow step gave no
+  `prompt:` (and legacy rows carrying the hub's old baked-in English
+  sentence) now renders the localized fallback "Freigabe für diesen
+  Schritt erforderlich" / "Approval required for this step" — no more
+  English inside the German approvals UI.
+- **Approving without review data asks first.** When the approval step
+  attached no `show:` payload, "Freigeben" opens a calm confirmation
+  ("Ohne Prüfdaten freigeben?") explaining that the flow deliberately
+  attached no data, with an explicit "Trotzdem freigeben".
+- **Studio error log moved to `~/.chain/logs/`.** Writes went to the
+  pre-rename `~/.fai/logs/studio-errors.log` while the Doctor page and
+  `chain doctor` read `~/.chain/…`. Studio now writes to `.chain` and
+  migrates the old file (+ rotation sibling) over once.
+- **Honest audit wording (legal review).** DE strings no longer claim
+  "manipulationssicher" — the audit log is *manipulationserkennend*
+  (tamper-evident); "warum WORM-1 für KRITIS reicht" became a neutral
+  what-it-does-and-does-not sentence (EN too); the Doctor chain pill
+  says "Integritätskette v1" instead of "WORM-1"; the federation
+  enrollment hint says the CA *authenticates* the first connect.
+- **WCAG-AA secondary text on dark.** De-emphasised text was 3.7:1 on
+  cards; the muted token is now ≥ 4.5:1 against canvas, cards and
+  elevated surfaces.
+
 ### Added
 
 - **Live audit feed.** The Audit page subscribes to `streamEvents` and

lib/data/chain_log.dart

@@ -51,7 +51,31 @@ class ChainLog {
         Platform.environment['HOME'] ??
         Platform.environment['USERPROFILE'] ??
         '.';
-    return p.join(home, '.fai', 'logs', 'studio-errors.log');
+    final path = p.join(home, '.chain', 'logs', 'studio-errors.log');
+    _migrateLegacyLog(home, path);
+    return path;
+  }
+
+  // Pre-rename installs wrote to `~/.fai/logs/`. Move that file (and
+  // its rotation sibling) over once so the error trail survives the
+  // rename; never overwrite an existing new-path file. Best-effort
+  // and cheap enough to run per access (two stat calls after the
+  // first migration).
+  static void _migrateLegacyLog(String home, String newPath) {
+    try {
+      for (final suffix in const ['', '.1']) {
+        final legacy = File(
+          p.join(home, '.fai', 'logs', 'studio-errors.log$suffix'),
+        );
+        final target = File('$newPath$suffix');
+        if (legacy.existsSync() && !target.existsSync()) {
+          target.parent.createSync(recursive: true);
+          legacy.renameSync(target.path);
+        }
+      }
+    } catch (_) {
+      // Best-effort: a failed migration must not break logging.
+    }
   }
 
   /// Absolute path of the studio-errors log. Public so the

lib/l10n/app_de.arb

@@ -30,7 +30,7 @@
   "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.",
-  "welcomeTrustAuditTitle": "Manipulationssicheres Audit-Log",
+  "welcomeTrustAuditTitle": "Manipulationserkennendes Audit-Log",
   "welcomeTrustAuditBody": "Flow-Läufe, Installationen, Deinstallationen, Freigabe-Entscheidungen — alles wird in ein hash-verkettetes Audit-Log geschrieben. Die Diagnose-Seite verifiziert die Kette bei jedem Laden komplett.",
   "welcomeTrustAirgapTitle": "Air-Gap-tauglich",
   "welcomeTrustAirgapBody": "Der gesamte Hub steckt in einem einzigen Binary für Linux, macOS und Windows. Sobald ein Modul installiert ist, läuft der Flow, der es nutzt, ohne weiteren Netzwerkzugriff — ideal für regulierte Umgebungen.",
@@ -40,8 +40,8 @@
   "welcomeDocArchitectureBlurb": "Hub, Modul, Flow — und wie die drei zusammenpassen.",
   "welcomeDocSecurityTitle": "Sandbox-Modell",
   "welcomeDocSecurityBlurb": "Was ein Modul deklariert, was der Operator deckelt, was der Hub durchsetzt.",
-  "welcomeDocAuditTitle": "Manipulationssicheres Audit-Log",
+  "welcomeDocAuditTitle": "Manipulationserkennendes Audit-Log",
-  "welcomeDocAuditBlurb": "Wie die Hash-Kette funktioniert und warum WORM-1 für KRITIS reicht.",
+  "welcomeDocAuditBlurb": "Wie die Hash-Kette nachträgliche Änderungen erkennbar macht — und was die Integritätsstufe WORM-1 leistet (und was nicht).",
   "welcomeDocFlowsTitle": "Flow-Komposition",
   "welcomeDocFlowsBlurb": "YAML-Grundlagen, Templating-Referenz, das Extract→Summarize-Beispiel.",
   "welcomeDocApprovalsTitle": "Freigaben",
@@ -1046,6 +1046,9 @@
   "approvalsPillExpired": "abgelaufen",
   "approvalsPayloadPreview": "ZU PRÜFENDE DATEN",
   "approvalsNoPayload": "Keine Daten zum Prüfen angehängt. Der system.approval-Schritt des Flows bestimmt über sein \"show:\"-Feld, was angezeigt wird — setze es, um die Daten hinter dieser Entscheidung sichtbar zu machen.",
+  "approvalsNoDataConfirmTitle": "Ohne Prüfdaten freigeben?",
+  "approvalsNoDataConfirmBody": "Dieser Flow hat bewusst keine Prüfdaten hinterlegt (kein \"show:\" am Freigabe-Schritt). Du kannst trotzdem freigeben — entscheidest dann aber, ohne die Daten hinter dieser Entscheidung gesehen zu haben.",
+  "approvalsNoDataConfirmAction": "Trotzdem freigeben",
   "approvalsRequestFallback": "Freigabe für diesen Schritt erforderlich",
   "approvalsFlowStepMeta": "Flow: {flow} · Schritt: {step}",
   "approvalsApproveButton": "Freigeben",
@@ -1193,7 +1196,7 @@
       }
     }
   },
-  "doctorChainPillOk": "WORM-1",
+  "doctorChainPillOk": "Integritätskette v1",
   "doctorChainPillTamper": "MANIPULIERT",
   "doctorVerifyNow": "Jetzt prüfen",
   "doctorRestart": "Neustart",
@@ -1661,5 +1664,5 @@
   "federationTokenLabel": "Bootstrap-Token (einmalig)",
   "federationConfigLabel": "Satelliten-Konfiguration (in den Satelliten einfügen)",
   "federationCopied": "In die Zwischenablage kopiert",
-  "federationEnrollmentHint": "Übergib das Token dem Satelliten-Betreiber über einen sicheren Kanal. Die mitgelieferte CA macht den ersten Connect des Satelliten manipulationssicher."
+  "federationEnrollmentHint": "Übergib das Token dem Satelliten-Betreiber über einen sicheren Kanal. Die mitgelieferte CA authentifiziert den ersten Connect des Satelliten."
 }

lib/l10n/app_en.arb

@@ -49,7 +49,7 @@
   "welcomeDocSecurityTitle": "Sandbox model",
   "welcomeDocSecurityBlurb": "What a module declares, what the operator caps, what the hub enforces.",
   "welcomeDocAuditTitle": "Tamper-evident audit log",
-  "welcomeDocAuditBlurb": "How the hash chain works and why WORM-1 is enough for KRITIS.",
+  "welcomeDocAuditBlurb": "How the hash chain makes later edits detectable — and what integrity level WORM-1 does (and does not) provide.",
   "welcomeDocFlowsTitle": "Flow composition",
   "welcomeDocFlowsBlurb": "YAML basics, templating reference, the extract→summarize example.",
   "welcomeDocApprovalsTitle": "Approvals",
@@ -1064,6 +1064,9 @@
   "approvalsPillExpired": "expired",
   "approvalsPayloadPreview": "DATA TO REVIEW",
   "approvalsNoPayload": "No data was attached for review. The flow's approval step chooses what to show via its \"show:\" field — set it to surface the data behind this decision.",
+  "approvalsNoDataConfirmTitle": "Approve without review data?",
+  "approvalsNoDataConfirmBody": "This flow deliberately attached no review data (no \"show:\" on its approval step). You can still approve — but you would be deciding without seeing the data behind this decision.",
+  "approvalsNoDataConfirmAction": "Approve anyway",
   "approvalsRequestFallback": "Approval required for this step",
   "approvalsFlowStepMeta": "Flow: {flow} · Step: {step}",
   "@approvalsFlowStepMeta": {
@@ -1217,7 +1220,7 @@
       }
     }
   },
-  "doctorChainPillOk": "WORM-1",
+  "doctorChainPillOk": "Integrity chain v1",
   "doctorChainPillTamper": "TAMPER",
   "doctorVerifyNow": "Verify now",
   "doctorRestart": "Restart",
@@ -1700,5 +1703,5 @@
   "federationTokenLabel": "Bootstrap token (single use)",
   "federationConfigLabel": "Satellite config (paste into the satellite)",
   "federationCopied": "Copied to clipboard",
-  "federationEnrollmentHint": "Hand the token to the satellite operator over a secure channel. The bundled CA makes the satellite's first connect tamper-proof."
+  "federationEnrollmentHint": "Hand the token to the satellite operator over a secure channel. The bundled CA authenticates the satellite's first connect."
 }

lib/l10n/app_localizations.dart

@@ -347,7 +347,7 @@ abstract class AppLocalizations {
   /// No description provided for @welcomeDocAuditBlurb.
   ///
   /// In en, this message translates to:
-  /// **'How the hash chain works and why WORM-1 is enough for KRITIS.'**
+  /// **'How the hash chain makes later edits detectable — and what integrity level WORM-1 does (and does not) provide.'**
   String get welcomeDocAuditBlurb;
 
   /// No description provided for @welcomeDocFlowsTitle.
@@ -3254,6 +3254,24 @@ abstract class AppLocalizations {
   /// **'No data was attached for review. The flow\'s approval step chooses what to show via its \"show:\" field — set it to surface the data behind this decision.'**
   String get approvalsNoPayload;
 
+  /// No description provided for @approvalsNoDataConfirmTitle.
+  ///
+  /// In en, this message translates to:
+  /// **'Approve without review data?'**
+  String get approvalsNoDataConfirmTitle;
+
+  /// No description provided for @approvalsNoDataConfirmBody.
+  ///
+  /// In en, this message translates to:
+  /// **'This flow deliberately attached no review data (no \"show:\" on its approval step). You can still approve — but you would be deciding without seeing the data behind this decision.'**
+  String get approvalsNoDataConfirmBody;
+
+  /// No description provided for @approvalsNoDataConfirmAction.
+  ///
+  /// In en, this message translates to:
+  /// **'Approve anyway'**
+  String get approvalsNoDataConfirmAction;
+
   /// No description provided for @approvalsRequestFallback.
   ///
   /// In en, this message translates to:
@@ -3527,7 +3545,7 @@ abstract class AppLocalizations {
   /// No description provided for @doctorChainPillOk.
   ///
   /// In en, this message translates to:
-  /// **'WORM-1'**
+  /// **'Integrity chain v1'**
   String get doctorChainPillOk;
 
   /// No description provided for @doctorChainPillTamper.
@@ -4870,7 +4888,7 @@ abstract class AppLocalizations {
   /// No description provided for @federationEnrollmentHint.
   ///
   /// In en, this message translates to:
-  /// **'Hand the token to the satellite operator over a secure channel. The bundled CA makes the satellite\'s first connect tamper-proof.'**
+  /// **'Hand the token to the satellite operator over a secure channel. The bundled CA authenticates the satellite\'s first connect.'**
   String get federationEnrollmentHint;
 }
 

lib/l10n/app_localizations_de.dart

@@ -110,7 +110,7 @@ class AppLocalizationsDe extends AppLocalizations {
       'Jedes Modul bringt eine explizite Berechtigungsliste mit — Netzwerk-Endpunkte, Dateien, Umgebungsvariablen. Der Hub setzt sie durch; ohne Operator-Freigabe verlässt nichts die Sandbox.';
 
   @override
-  String get welcomeTrustAuditTitle => 'Manipulationssicheres Audit-Log';
+  String get welcomeTrustAuditTitle => 'Manipulationserkennendes Audit-Log';
 
   @override
   String get welcomeTrustAuditBody =>
@@ -145,11 +145,11 @@ class AppLocalizationsDe extends AppLocalizations {
       'Was ein Modul deklariert, was der Operator deckelt, was der Hub durchsetzt.';
 
   @override
-  String get welcomeDocAuditTitle => 'Manipulationssicheres Audit-Log';
+  String get welcomeDocAuditTitle => 'Manipulationserkennendes Audit-Log';
 
   @override
   String get welcomeDocAuditBlurb =>
-      'Wie die Hash-Kette funktioniert und warum WORM-1 für KRITIS reicht.';
+      'Wie die Hash-Kette nachträgliche Änderungen erkennbar macht — und was die Integritätsstufe WORM-1 leistet (und was nicht).';
 
   @override
   String get welcomeDocFlowsTitle => 'Flow-Komposition';
@@ -1871,6 +1871,16 @@ class AppLocalizationsDe extends AppLocalizations {
   String get approvalsNoPayload =>
       'Keine Daten zum Prüfen angehängt. Der system.approval-Schritt des Flows bestimmt über sein \"show:\"-Feld, was angezeigt wird — setze es, um die Daten hinter dieser Entscheidung sichtbar zu machen.';
 
+  @override
+  String get approvalsNoDataConfirmTitle => 'Ohne Prüfdaten freigeben?';
+
+  @override
+  String get approvalsNoDataConfirmBody =>
+      'Dieser Flow hat bewusst keine Prüfdaten hinterlegt (kein \"show:\" am Freigabe-Schritt). Du kannst trotzdem freigeben — entscheidest dann aber, ohne die Daten hinter dieser Entscheidung gesehen zu haben.';
+
+  @override
+  String get approvalsNoDataConfirmAction => 'Trotzdem freigeben';
+
   @override
   String get approvalsRequestFallback =>
       'Freigabe für diesen Schritt erforderlich';
@@ -2043,7 +2053,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get doctorChainPillOk => 'WORM-1';
+  String get doctorChainPillOk => 'Integritätskette v1';
 
   @override
   String get doctorChainPillTamper => 'MANIPULIERT';
@@ -2860,5 +2870,5 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get federationEnrollmentHint =>
-      'Übergib das Token dem Satelliten-Betreiber über einen sicheren Kanal. Die mitgelieferte CA macht den ersten Connect des Satelliten manipulationssicher.';
+      'Übergib das Token dem Satelliten-Betreiber über einen sicheren Kanal. Die mitgelieferte CA authentifiziert den ersten Connect des Satelliten.';
 }

lib/l10n/app_localizations_en.dart

@@ -150,7 +150,7 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get welcomeDocAuditBlurb =>
-      'How the hash chain works and why WORM-1 is enough for KRITIS.';
+      'How the hash chain makes later edits detectable — and what integrity level WORM-1 does (and does not) provide.';
 
   @override
   String get welcomeDocFlowsTitle => 'Flow composition';
@@ -1882,6 +1882,16 @@ class AppLocalizationsEn extends AppLocalizations {
   String get approvalsNoPayload =>
       'No data was attached for review. The flow\'s approval step chooses what to show via its \"show:\" field — set it to surface the data behind this decision.';
 
+  @override
+  String get approvalsNoDataConfirmTitle => 'Approve without review data?';
+
+  @override
+  String get approvalsNoDataConfirmBody =>
+      'This flow deliberately attached no review data (no \"show:\" on its approval step). You can still approve — but you would be deciding without seeing the data behind this decision.';
+
+  @override
+  String get approvalsNoDataConfirmAction => 'Approve anyway';
+
   @override
   String get approvalsRequestFallback => 'Approval required for this step';
 
@@ -2052,7 +2062,7 @@ class AppLocalizationsEn extends AppLocalizations {
   }
 
   @override
-  String get doctorChainPillOk => 'WORM-1';
+  String get doctorChainPillOk => 'Integrity chain v1';
 
   @override
   String get doctorChainPillTamper => 'TAMPER';
@@ -2863,5 +2873,5 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get federationEnrollmentHint =>
-      'Hand the token to the satellite operator over a secure channel. The bundled CA makes the satellite\'s first connect tamper-proof.';
+      'Hand the token to the satellite operator over a secure channel. The bundled CA authenticates the satellite\'s first connect.';
 }

lib/pages/approvals.dart

@@ -10,6 +10,24 @@ import '../theme/tokens.dart';
 import '../widgets/widgets.dart';
 import 'welcome.dart' show showFaiDoc;
 
+/// The fixed English sentence pre-0.21 hubs baked into stored
+/// approvals when the flow gave no `prompt:`. Newer hubs store the
+/// empty prompt verbatim.
+const _legacyHubPromptDefault =
+    'Please review and approve this step before continuing.';
+
+/// Reviewer-facing prompt with fallbacks: an empty prompt (the flow
+/// gave none) renders the localized default, and the legacy English
+/// default from old hub rows is mapped onto the same localized
+/// default so it stops showing English inside a German UI.
+String displayApprovalPrompt(AppLocalizations l, String prompt) {
+  final trimmed = prompt.trim();
+  if (trimmed.isEmpty || trimmed == _legacyHubPromptDefault) {
+    return l.approvalsRequestFallback;
+  }
+  return prompt;
+}
+
 class ApprovalsPage extends StatefulWidget {
   const ApprovalsPage({super.key});
 
@@ -68,6 +86,29 @@ class _ApprovalsPageState extends State<ApprovalsPage>
 
   Future<void> _approve(ApprovalRecord a) async {
     final l = AppLocalizations.of(context)!;
+    // No `show:` data attached → never approve on a reflex. Calmly
+    // explain and ask for a conscious confirmation first.
+    if (a.payloadPreview == null) {
+      final confirmed = await showDialog<bool>(
+        context: context,
+        builder: (ctx) => AlertDialog(
+          title: Text(l.approvalsNoDataConfirmTitle),
+          content: Text(l.approvalsNoDataConfirmBody),
+          actions: [
+            TextButton(
+              onPressed: () => Navigator.pop(ctx, false),
+              child: Text(l.buttonCancel),
+            ),
+            FilledButton(
+              onPressed: () => Navigator.pop(ctx, true),
+              child: Text(l.approvalsNoDataConfirmAction),
+            ),
+          ],
+        ),
+      );
+      if (confirmed != true) return;
+    }
+    if (!mounted) return;
     try {
       await HubService.instance.approve(a.id, _reviewer);
       _toast(l.approvalsApprovedToast(a.flowName, a.stepId));
@@ -77,6 +118,7 @@ class _ApprovalsPageState extends State<ApprovalsPage>
     }
   }
 
+
   Future<void> _reject(ApprovalRecord a) async {
     final l = AppLocalizations.of(context)!;
     final reason = await _promptReason(context);
@@ -558,9 +600,7 @@ class _ApprovalCard extends StatelessWidget {
           // step left the prompt empty, so the card is never reduced to
           // a cryptic flow id.
           Text(
-            approval.prompt.trim().isEmpty
+            displayApprovalPrompt(l, approval.prompt),
-                ? l.approvalsRequestFallback
-                : approval.prompt,
             style: theme.textTheme.titleMedium?.copyWith(
               fontWeight: FontWeight.w600,
             ),
@@ -850,7 +890,13 @@ class _HistoryDialog extends StatelessWidget {
                 ),
               ),
               const SizedBox(height: 4),
-              SelectableText(record.prompt, style: theme.textTheme.bodyMedium),
+              SelectableText(
+                displayApprovalPrompt(
+                  AppLocalizations.of(context)!,
+                  record.prompt,
+                ),
+                style: theme.textTheme.bodyMedium,
+              ),
               if (record.payloadPreview != null) ...[
                 const SizedBox(height: ChainSpace.md),
                 Text(

lib/pages/store.dart

@@ -3252,7 +3252,7 @@ const List<TodayStoryData> _kFallbackTodayStories = <TodayStoryData>[
     badgeEn: 'AUDIT',
     badgeDe: 'AUDIT',
     titleEn: 'Tamper-evident hash chain — built in',
-    titleDe: 'Manipulationssicher per Hash-Kette — eingebaut',
+    titleDe: 'Manipulation erkennbar per Hash-Kette — eingebaut',
     bodyEn:
         'Every flow run, every install, every approval lands in ~/.chain/audit/ as a hash-chained event log. Any later edit invalidates the chain. CRA-ready out of the box — no compliance product to buy on top.',
     bodyDe:

lib/theme/tokens.dart

@@ -27,7 +27,9 @@ class ChainColors {
   static const surface = Color(0xFF18181B); // cards
   static const surfaceHigh = Color(0xFF27272A); // elevated
   static const border = Color(0xFF3F3F46); // 1px outlines
-  static const muted = Color(0xFF71717A); // de-emphasised text
+  // De-emphasised text. WCAG AA (≥4.5:1) against canvas, cards AND
+  // elevated surfaces — 0xFF71717A only reached 3.7:1 on cards.
+  static const muted = Color(0xFF8E8E97);
   static const text = Color(0xFFE4E4E7); // body
   static const textStrong = Color(0xFFFAFAFA); // headings