feat(studio): carousel size lock, store-actionable today stories, HTTPS MCP suggestions in settings (v0.36.0)

Three concrete changes against operator feedback that the
Today carousel was visually jumping when arrowed and
genre-mixing platform-architecture education with store-
actionable highlights.

- Carousel size pinned. The hero's outer Container picks up
  `BoxConstraints(minHeight: 240)` so a slide with one
  paragraph and a slide with three render at the same
  height. Prev/next no longer reflows the rest of the page.

- Today fallback stories trimmed and re-themed. The four
  shipped slides drop to three:
  - "Public sources" (DeepWiki / Semgrep one-click) — kept
  - "Three text modules already in the store" — new,
    points the operator at text.extract / text.summarize /
    text.translate in the grid below
  - "Try the extract → summarize flow" — new, points at
    flows/extract-summarize.yaml
  Architecture-education stories (sandbox model, hash-
  chained audit, air-gap posture) are gone from this surface
  — they belong on the Welcome page that
  `docs/landing-page-design.md` lays out.

- DeepWiki + Semgrep added to the Settings → MCP-Clients
  add-server suggestion-chip catalogue. Until now the chips
  were nine stdio servers that need Node + npx; the two
  HTTPS public sources only existed as one-click cards in
  the Today hero. Operators who dismissed the hero had no
  in-Settings path to find them. The new entries sit at the
  top of the catalogue with an explicit "Public HTTPS — no
  Node, no API key" descriptor and the same icons the Today
  hero already uses.

- `docs/landing-page-design.md` (new). Captures the design
  for a sidebar Welcome page that hosts the three-pillar
  intro, the trust-posture deck, the getting-started
  checklist, and an embedded-doc reader so operator-facing
  documentation stays inside Studio (`flutter_markdown`
  rendering of bundled `assets/docs/*.md`) instead of
  clicking out to a browser. Three-phase implementation
  plan: scaffolding, embedded docs, computed checklist.
  Build is gated on operator alignment; this doc is the
  alignment artefact.

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

lib/main.dart

@@ -25,7 +25,7 @@ import 'widgets/widgets.dart';
 /// Studio's own build version. Bump on every UI commit so the
 /// running app self-identifies — visible in the sidebar header
 /// and quick-glance proof that you're seeing the current build.
-const String kStudioVersion = '0.35.0';
+const String kStudioVersion = '0.36.0';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();