feat: onboarding polish, splash screen, controller nav, dev script

Onboarding flow:
- Intro: improved layout and transitions
- DID: better card styling and responsiveness
- Path: added visual enhancements
- Backup/Identity/Verify: streamlined markup
- SplashScreen component added

UI:
- Controller navigation improvements (useControllerNav)
- Style.css refinements

Backend:
- Runtime package fix

Dev:
- dev-start.sh improvements

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/composables/useControllerNav.ts

@@ -115,7 +115,14 @@ function findNearestInDirection(
 
   scored.sort((a, b) => {
     if (b.overlap !== a.overlap) return b.overlap - a.overlap
-    return a.dist - b.dist
+    if (a.dist !== b.dist) return a.dist - b.dist
+    // Tiebreaker for up/down: prefer leftmost element in grid layouts
+    if (direction === 'up' || direction === 'down') {
+      const aLeft = a.el.getBoundingClientRect().left
+      const bLeft = b.el.getBoundingClientRect().left
+      return aLeft - bLeft
+    }
+    return 0
   })
   return scored[0]?.el ?? null
 }
@@ -149,7 +156,7 @@ export function useControllerNav(containerRef?: { value: HTMLElement | null }) {
 
     const target = e.target as HTMLElement
     if (target.tagName === 'INPUT' || target.tagName === 'TEXTAREA') {
-      // Enter in text field: blur and move to next focusable element (e.g., submit button)
+      // Enter in text field: find next focusable — if it's a button, click it directly (submit)
       if (e.key === 'Enter' && target.tagName === 'INPUT' && (target as HTMLInputElement).type !== 'submit') {
         e.preventDefault()
         const root = containerRef?.value ?? document
@@ -157,12 +164,24 @@ export function useControllerNav(containerRef?: { value: HTMLElement | null }) {
         const idx = all.indexOf(target as HTMLElement)
         const next = idx >= 0 ? all[idx + 1] : undefined
         if (next) {
-          next.focus()
-          next.scrollIntoView({ block: 'nearest', behavior: 'smooth' })
+          if (next.tagName === 'BUTTON' || next.getAttribute('role') === 'button') {
+            next.focus()
+            next.click()
+          } else {
+            next.focus()
+            next.scrollIntoView({ block: 'nearest', behavior: 'smooth' })
+          }
         }
         return
       }
-      if (e.key !== 'Escape') return
+      // Up/Down arrows: exit field and navigate to element above/below
+      if (e.key === 'ArrowUp' || e.key === 'ArrowDown') {
+        e.preventDefault()
+        ;(target as HTMLElement).blur()
+        // Fall through to arrow key handling below
+      } else if (e.key !== 'Escape') {
+        return
+      }
     }
 
     const root = containerRef?.value ?? document