feat(shell): home menu + navigation drawer (mockups 02/03)

The app now opens on a main menu instead of straight into the list:
- HomeScreen (mockup 02): sprout logo over a faint seed-glyph watermark, with
  big "Your inventory" (→ /inventory) and "Open market" (Block 2, "coming soon")
  destinations.
- AppDrawer (mockup 03): Inventory is live; the social items (market, profile,
  chat, wishlist, following, settings) are shown disabled with a "coming soon"
  tag so the roadmap is visible. Drawer is available on home and inventory.
- Routing: / → home, /inventory → list, /variety/:id → detail.

Tests: home shows the menu + navigates; drawer opens + navigates. quick-add flow
updated to go home → inventory. 50 green; Linux runs.

apps/app_seeds/lib/ui/app_drawer.dart

@@ -0,0 +1,115 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+import 'package:material_symbols_icons/symbols.dart';
+
+import '../i18n/strings.g.dart';
+import 'seed_glyph.dart';
+import 'theme.dart';
+
+/// The app's navigation drawer (mockup 03). Inventory is live; the social items
+/// (market, profile, chat…) belong to Block 2 and are shown disabled with a
+/// "coming soon" tag so the roadmap is visible.
+class AppDrawer extends StatelessWidget {
+  const AppDrawer({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final t = context.t;
+    return Drawer(
+      backgroundColor: Colors.white,
+      child: SafeArea(
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            const _DrawerHeader(),
+            _ActiveItem(
+              icon: const SeedGlyph(SeedGlyphs.jars, size: 22),
+              label: t.menu.inventory,
+              onTap: () {
+                Navigator.of(context).pop();
+                context.go('/inventory');
+              },
+            ),
+            _SoonItem(icon: Symbols.storefront, label: t.menu.market),
+            const Divider(),
+            _SoonItem(icon: Icons.person_outline, label: t.menu.profile),
+            _SoonItem(icon: Icons.chat_bubble_outline, label: t.menu.chat),
+            _SoonItem(icon: Icons.favorite_border, label: t.menu.wishlist),
+            _SoonItem(icon: Icons.group_outlined, label: t.menu.following),
+            const Spacer(),
+            const Divider(),
+            _SoonItem(icon: Icons.settings_outlined, label: t.menu.settings),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _DrawerHeader extends StatelessWidget {
+  const _DrawerHeader();
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
+      child: Row(
+        children: [
+          const Icon(Symbols.eco, color: seedGreen, size: 32),
+          const SizedBox(width: 12),
+          Text(
+            context.t.app.title,
+            style: Theme.of(context).textTheme.titleLarge?.copyWith(
+              color: seedGreenDark,
+              fontWeight: FontWeight.bold,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _ActiveItem extends StatelessWidget {
+  const _ActiveItem({
+    required this.icon,
+    required this.label,
+    required this.onTap,
+  });
+
+  final Widget icon;
+  final String label;
+  final VoidCallback onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      leading: SizedBox(width: 24, child: Center(child: icon)),
+      title: Text(label),
+      onTap: onTap,
+    );
+  }
+}
+
+/// A disabled Block-2 destination with a subtle "coming soon" tag.
+class _SoonItem extends StatelessWidget {
+  const _SoonItem({required this.icon, required this.label});
+
+  final IconData icon;
+  final String label;
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      enabled: false,
+      leading: Icon(icon),
+      title: Text(label),
+      trailing: Text(
+        context.t.common.comingSoon,
+        style: Theme.of(
+          context,
+        ).textTheme.labelSmall?.copyWith(color: Colors.black38),
+      ),
+    );
+  }
+}