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/l10n/app_de.arb

@@ -1423,5 +1423,23 @@
     "placeholders": {
       "name": {"type": "String"}
     }
-  }
+  },
+  "buttonView": "Ansehen",
+  "logViewerTitle": "{title} — letzte {count} Zeilen",
+  "@logViewerTitle": {
+    "placeholders": {
+      "title": {"type": "String"},
+      "count": {"type": "int"}
+    }
+  },
+  "logViewerEmpty": "Log-Datei ist leer oder existiert noch nicht.",
+  "logViewerCopyAll": "Alles kopieren",
+  "logViewerOpenExternal": "Im Standardeditor öffnen",
+  "logViewerLineCount": "{count, plural, =1{1 Zeile} other{{count} Zeilen}}",
+  "@logViewerLineCount": {
+    "placeholders": {
+      "count": {"type": "int"}
+    }
+  },
+  "doctorPathStudioErrors": "Studio-Fehler"
 }