rebrand: Jarvis -> Jervis for App Store submission

"JARVIS" is Marvel's trademark for the Iron Man/Avengers AI — real
legal risk for a commercial App Store listing, and the name is already
contested there ("Jarvis: Powered by Marvel", "Jarvis - AI Chatbot").
Jervis reads identically but doesn't collide.

Scoped to user-facing surfaces only:
- CFBundleDisplayName, PRODUCT_BUNDLE_IDENTIFIER (com.kisani.jervis)
- BGTaskSchedulerPermittedIdentifiers + matching Swift constants
- NSLocalNetworkUsageDescription permission prompt copy
- JarvisWordmark rendered text ("j" + "ervis")
- Notification permission prompt copy

Internal Xcode target/executable name, Swift type names (JarvisWordmark,
JarvisApp), file/folder names, and repo name are unchanged — renaming
those is a separate, larger refactor with no user-facing benefit.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Jarvis/Views/Shared/Theme.swift

@@ -363,7 +363,7 @@ struct JarvisWordmark: View {
     var body: some View {
         HStack(spacing: 0) {
             Text("j").font(font).foregroundStyle(Palette.orange)
-            Text("arvis").font(font).foregroundStyle(Palette.primaryText)
+            Text("ervis").font(font).foregroundStyle(Palette.primaryText)
         }
     }
 }