feat: add CLAUDE.md with iOS app and ecosystem context

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

Author: vveerrgg

CLAUDE.md

@@ -0,0 +1,44 @@
+# CLAUDE.md — nostrkey.app.ios.src
+
+## What This Is
+NostrKey iOS app — native wrapper that runs the full NostrKey browser extension UI on iOS with native platform integrations (QR scanner, clipboard, lock screen npub display).
+
+## Ecosystem Position
+Mobile surface for NostrKey — the key management layer. Same role as the browser extension but on iOS. Uses dual-WKWebView architecture with IOSBridge.swift bridging JS to native APIs.
+
+## Current Version
+v1.1.1 — Bundled extension v1.5.4 — App Store submission in progress
+
+## Tech Stack
+- Swift 5.9, Xcode 15.0+
+- Dual-WKWebView (background + UI)
+- IOSBridge.swift (`WKScriptMessageHandler`)
+- ios-polyfill.js maps `chrome.storage`/`chrome.runtime` to bridge calls
+- UserDefaults for storage
+- AVFoundation for QR scanning
+- xcodegen for project generation
+
+## Build
+```bash
+xcodegen generate
+open NostrKey.xcodeproj
+# Build & Run in Xcode
+```
+
+## Key Differences from Browser Extension
+- Storage: UserDefaults (not `chrome.storage`)
+- QR scanning: AVFoundation (native)
+- No `window.nostr` injection
+- No cross-device sync yet
+- Lock screen QR code + npub display (iOS-only features)
+
+## Planned
+- App Store listing
+- App Groups (share profiles between iOS app ↔ Safari extension)
+- Biometric unlock (Face ID / Touch ID)
+- Deep links (`nostr:` URIs)
+
+## Related Repos
+- `nostrkey.browser.plugin.src` — core extension code (bundled here as web assets)
+- `nostrkey.app.android.src` — Android equivalent
+- `nostrkey.bizdocs.src` — business strategy