feat(studio): hub maintenance panel with reset action (v0.45.0)

UI parity with the platform CLI: `fai reset` (v0.10.93) is now
reachable from Settings. The panel shows the reset blurb plus
two checkboxes mirroring the CLI flags (Keep modules / Keep
audit log + saved flows), then a destructive-styled "Reset hub
state" button. Click goes through a confirm dialog before
SystemActions.faiReset is invoked.

After the CLI returns, Studio bounces its gRPC channel against
the same endpoint (the daemon restarts on the same channel +
port, so no Settings change needed) and reloads every panel:
channel status, system AI, MCP clients, n8n endpoints, registry
token. Output (success or failure) is shown in a copyable error
box so any unexpected stderr lands somewhere the operator can
paste from.

Sits at the bottom of the dialog under "HUB MAINTENANCE",
separated from the everyday config so a destructive button
doesn't crowd the day-to-day controls.

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

lib/l10n/app_en.arb

@@ -450,6 +450,17 @@
   "@registryTokenSaveFailedToast": {
     "placeholders": { "error": { "type": "String" } }
   },
+  "maintenanceHeader": "HUB MAINTENANCE",
+  "maintenanceResetBlurb": "Wipe operator state and start over with a clean hub. Stops every running daemon, atomically backs ~/.fai/ up, then recreates it with the binary, channel state, MCP / n8n / system-AI config, and registry token preserved. Restore by moving the backup directory back.",
+  "maintenanceKeepModulesTitle": "Keep installed modules",
+  "maintenanceKeepModulesSubtitle": "Default behaviour wipes ~/.fai/modules/ so a fresh install can verify the module-fetch path end-to-end.",
+  "maintenanceKeepDataTitle": "Keep audit log + saved flows",
+  "maintenanceKeepDataSubtitle": "Default behaviour wipes ~/.fai/data/ so the audit chain restarts from a fresh genesis and the bundled sample flows re-import on first daemon start.",
+  "maintenanceResetButton": "Reset hub state",
+  "maintenanceResetInProgress": "Resetting…",
+  "maintenanceResetConfirmTitle": "Reset hub state?",
+  "maintenanceResetConfirmBody": "This stops every daemon, moves ~/.fai/ to a timestamped backup, and starts fresh. The backup is fully restorable. Continue?",
+  "maintenanceResetConfirmButton": "Reset",
   "welcomeChecklistAllSetTitle": "You're set up.",
   "welcomeChecklistAllSetBody": "Three threads to pull on next:",
   "welcomeChecklistNextAuditTitle": "Read the audit log",