feat(editor): localised analyzer/strip/run messages + monospace font fallback

Closes operator-reported issues around the text-tab font and
the English-only run + diagnostic surfaces.

  - **Real monospace everywhere**. The package never bundled
    JetBrains Mono as an asset (it relied on Studio's
    google_fonts pre-load), so a host that doesn't ship the
    font saw the YAML editor render in the system proportional
    default. New _monoTextStyle() pins fontFamilyFallback to a
    cross-platform monospace chain (Menlo / Consolas / Courier
    New / monospace) so the editor stays a grid in every host.
    Applied to the code field, gutter, diagnostic strip,
    issue rows, hover card, fix buttons, and the run tab's
    error box.

  - **Locale-aware analyzer messages**. New AnalyzerStrings
    adapter holds every string the analyzer emits, with an
    .english default + an .from(FlowEditorStrings) factory.
    FlowYamlCodeController.setCapabilityProviders takes the
    strings; FlowEditorPage wires them from the active locale.
    The analyzer's 'Unknown capability', 'Did you mean',
    'Not in the store — install locally with fai install
    --link', 'Unknown input/output type', YAML parse errors,
    and every quick-fix label (Install / Add source / Use /
    Change to) now flip to DE when the editor's locale is DE.

  - **Localised run + diagnostic chrome**. The bottom strip's
    'No issues', '2 errors · 1 warning', 'Copy all'; the
    issue row's L-prefix + Copy tooltip; the hover card's
    L-prefix + Copy tooltip; the run-block tooltip + inline
    message ('2 Fehler verhindern den Lauf · siehe
    Diagnose-Leiste unten'); the step-row 'awaiting approval'
    suffix; the CopyableErrorBox's Copy / Copied tooltip —
    all now flow through FlowEditorStrings.

Bumped to 0.20.0.

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

lib/src/widgets/run_tab.dart

@@ -183,7 +183,10 @@ class _RunTabState extends State<RunTab> {
           if (_error != null) ...[
             const SizedBox(height: FaiSpace.lg),
             _section(theme, strings.runTitleFailed),
-            _CopyableErrorBox(text: _error.toString()),
+            _CopyableErrorBox(
+              text: _error.toString(),
+              strings: widget.strings,
+            ),
           ],
         ],
       ),
@@ -300,6 +303,7 @@ class _RunTabState extends State<RunTab> {
   }
 
   Widget _stepRow(ThemeData theme, String id, _StepState state) {
+    final strings = widget.strings;
     final IconData glyph;
     final Color color;
     String suffix = '';
@@ -317,7 +321,7 @@ class _RunTabState extends State<RunTab> {
       case _StepKind.awaiting:
         glyph = Icons.pause_circle_outline;
         color = theme.colorScheme.tertiary;
-        suffix = '  awaiting approval';
+        suffix = '  ${strings.runAwaitingApproval}';
     }
     final isError = state.kind == _StepKind.error &&
         state.error != null &&
@@ -347,7 +351,10 @@ class _RunTabState extends State<RunTab> {
             const SizedBox(height: 4),
             Padding(
               padding: const EdgeInsets.only(left: 24),
-              child: _CopyableErrorBox(text: state.error!),
+              child: _CopyableErrorBox(
+                text: state.error!,
+                strings: widget.strings,
+              ),
             ),
           ],
         ],
@@ -365,9 +372,7 @@ class _RunTabState extends State<RunTab> {
     return Row(
       children: [
         Tooltip(
-          message: blocked
-              ? '$errors error${errors == 1 ? '' : 's'} prevent the run'
-              : '',
+          message: blocked ? strings.runErrorsBlockTooltip(errors) : '',
           child: FilledButton.icon(
             onPressed: _running || widget.driver == null || blocked
                 ? null
@@ -389,8 +394,8 @@ class _RunTabState extends State<RunTab> {
           const SizedBox(width: FaiSpace.sm),
           Flexible(
             child: Text(
-              '$errors error${errors == 1 ? '' : 's'} prevent the run · '
-              'check the diagnostic strip',
+              '${strings.runErrorsBlockRun(errors)} · '
+              '${strings.runErrorsBlockHint}',
               style: theme.textTheme.bodySmall?.copyWith(
                 color: theme.colorScheme.error,
               ),
@@ -619,7 +624,8 @@ class _StepState {
 /// so flow_editor doesn't depend on Studio internals.
 class _CopyableErrorBox extends StatefulWidget {
   final String text;
-  const _CopyableErrorBox({required this.text});
+  final FlowEditorStrings strings;
+  const _CopyableErrorBox({required this.text, required this.strings});
 
   @override
   State<_CopyableErrorBox> createState() => _CopyableErrorBoxState();
@@ -661,7 +667,8 @@ class _CopyableErrorBoxState extends State<_CopyableErrorBox> {
           Align(
             alignment: Alignment.centerRight,
             child: Tooltip(
-              message: _justCopied ? 'Copied' : 'Copy',
+              message:
+                  _justCopied ? widget.strings.runCopied : widget.strings.runCopy,
               child: IconButton(
                 icon: Icon(
                   _justCopied ? Icons.check : Icons.content_copy,
@@ -682,6 +689,12 @@ class _CopyableErrorBoxState extends State<_CopyableErrorBox> {
                   widget.text,
                   style: TextStyle(
                     fontFamily: 'JetBrains Mono',
+                    fontFamilyFallback: const [
+                      'Menlo',
+                      'Consolas',
+                      'Courier New',
+                      'monospace',
+                    ],
                     fontSize: 12,
                     color: theme.colorScheme.onErrorContainer,
                   ),