feat(studio): Doctor + Modules localized + sparse-store federation nudge (v0.25.0)

Two threads.

Translation expansion: every visible string on the Doctor
page (section headers, status text, button labels, daemon-
control card, daemon-files panel, update banner) and the
Modules page (recent-activity strip, capabilities label,
uninstall dialog + toast) flips between DE and EN with the
sidebar toggle. Adds ~50 ARB keys split between
`app_en.arb` / `app_de.arb`. Pluralised + parametrised
strings (`{n} events verified`, `Running on {name}: {endpoint}`)
use the standard ICU placeholder syntax so future locales
slot in without code changes.

Sparse-store federation nudge: the Store page renders an
inline banner above the grid when the operator has zero
federated entries — single biggest store-fullness lever is
configuring an MCP server / n8n endpoint, so the banner
says exactly that and the button opens Settings straight
to the editor. Banner dismisses automatically the next
render after a federated entry appears.

Coverage stand for translation: Doctor + Modules + sidebar
+ page titles + nav + Cmd+K labels are bilingual. Settings
dialog, Approvals cards, Audit drilldown, MCP/n8n editors,
Store search hint + filter chips remain English-literal.
The infrastructure (ARB plumbing, generator hookup,
locale-notifier) means each follow-up surface is a
one-line ARB edit + one call-site swap.

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

pubspec.yaml

@@ -1,7 +1,7 @@
 name: fai_studio
 description: "F∆I Studio — desktop GUI for the F∆I hub"
 publish_to: 'none'
-version: 0.24.0
+version: 0.25.0
 
 environment:
   sdk: ^3.11.0-200.1.beta