feat(studio): central error helpers + inline log viewer + Today CTAs

Bundles the error-UX overhaul and the inline log viewer:

  - New `FaiLog` (`~/.fai/logs/studio-errors.log`, 256 KiB rotation,
    JSON-per-line). Every operator-visible failure is appended so
    `fai admin doctor` and the new viewer can show the trail
    without the operator having to reproduce the failure.
  - New `showFaiErrorSnack` / `showFaiErrorDialog` helpers wrap
    `FaiErrorBox` in copyable surfaces; 27 ad-hoc
    `SnackBar(content: Text(e.toString()))` sites swept to use
    them (settings, doctor, audit, store, module sheet, system-AI
    editor, flow output).
  - New `FaiLogViewer` modal (`showFaiLogViewer`) renders log
    files inline with line numbers, JSON-key + `[level]` token
    colouring, Copy-all, Refresh, Open-externally. Doctor's
    daemon-paths panel grows a "View" button next to "Open" for
    every `.log` row and now also lists the Studio errors log.
  - Today carousel: CTAs now actually re-run search after a
    `filterCategory` / `runQuery` story is tapped (was only
    flipping the chip state). Fallback story list bumped to 8.
  - Editor bumped to git ref carrying 0.15.0 (type-token
    colouring + analyzer diagnostics).

Studio bumped to 0.62.0.

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

lib/widgets/fai_flow_output.dart

@@ -19,6 +19,7 @@ import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_markdown_plus/flutter_markdown_plus.dart';
 
+import '../data/error_presentation.dart';
 import '../data/flow_output.dart';
 import '../data/format.dart';
 import '../data/system_actions.dart';
@@ -172,9 +173,7 @@ class _BytesView extends StatelessWidget {
       ).showSnackBar(SnackBar(content: Text(l.flowsOutputSavedAt(path))));
     } catch (e) {
       if (!context.mounted) return;
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(SnackBar(content: Text(l.flowsOutputSaveFailed('$e'))));
+      showFaiErrorSnack(context, 'flows.output.save', e);
     }
   }
 
@@ -235,10 +234,11 @@ class _FileView extends StatelessWidget {
     final target = uri.startsWith('file://') ? uri.substring(7) : uri;
     final r = await SystemActions.openInOs(target);
     if (!context.mounted || r.ok) return;
-    final l = AppLocalizations.of(context)!;
-    ScaffoldMessenger.of(
+    showFaiErrorSnack(
       context,
-    ).showSnackBar(SnackBar(content: Text(l.flowsOutputOpenFailed(r.stderr))));
+      'flows.output.open',
+      r.stderr.isEmpty ? 'open failed' : r.stderr,
+    );
   }
 
   @override