fix(electrobun): wizard creation flow + GitLab probe + shell detection + dropdown flip

- Git probe tries GitHub then GitLab for owner/repo shorthand
- Shows "Found on GitHub/GitLab" with platform indicator
- system.shells RPC detects installed shells (bash/zsh/fish/sh/dash)
- CustomDropdown flip logic uses 200px threshold for flip-up
- Project creation properly persists all wizard fields + adds card

ui-electrobun/src/mainview/WizardStep2.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import { onMount } from 'svelte';
   import { PROJECT_ICONS, ACCENT_COLORS } from './wizard-icons.ts';
   import {
     Terminal, Server, Globe, Code, Database, Cpu, Zap, Shield,
@@ -11,6 +12,7 @@
   } from 'lucide-svelte';
   import CustomDropdown from './ui/CustomDropdown.svelte';
   import CustomCheckbox from './ui/CustomCheckbox.svelte';
+  import { appRpc } from './rpc.ts';
 
   interface Props {
     projectName: string;
@@ -33,7 +35,29 @@
     isGitRepo, onUpdate,
   }: Props = $props();
 
-  const SHELLS = ['bash', 'zsh', 'fish', 'sh'];
+  let detectedShells = $state<Array<{ path: string; name: string }>>([]);
+  const FALLBACK_SHELLS = ['bash', 'zsh', 'fish', 'sh'];
+
+  onMount(async () => {
+    try {
+      const r = await appRpc.request['system.shells']({});
+      if (r?.shells?.length) {
+        detectedShells = r.shells;
+        // If current shellChoice is not in detected shells, select the first available
+        if (!r.shells.some(s => s.name === shellChoice)) {
+          onUpdate('shellChoice', r.shells[0].name);
+        }
+      }
+    } catch {
+      // Fallback — use hardcoded list
+    }
+  });
+
+  let shellItems = $derived(
+    detectedShells.length > 0
+      ? detectedShells.map(s => ({ value: s.name, label: `${s.name} (${s.path})` }))
+      : FALLBACK_SHELLS.map(sh => ({ value: sh, label: sh }))
+  );
 
   const ICON_MAP: Record<string, typeof Terminal> = {
     Terminal, Server, Globe, Code, Database, Cpu, Zap, Shield,
@@ -108,7 +132,7 @@
 
 <label class="wz-label">Shell</label>
 <CustomDropdown
-  items={SHELLS.map(sh => ({ value: sh, label: sh }))}
+  items={shellItems}
   selected={shellChoice}
   onSelect={v => onUpdate('shellChoice', v)}
 />