Migrate from .NET MAUI to Expo + Convex

Complete rewrite of Scry using TypeScript stack:

- Expo/React Native with Expo Router (file-based routing)
- Convex backend (serverless functions + real-time database)
- Adaptive camera system (expo-camera in Expo Go, Vision Camera in production)
- React Native Skia + fast-opencv for image processing
- GDPR-compliant auth setup with Zitadel OIDC (pending configuration)

Key features:
- Card recognition pipeline ported to TypeScript
- Perceptual hashing (192-bit color pHash)
- CLAHE preprocessing for lighting normalization
- Local SQLite cache with Convex sync
- Collection management with offline support

Removes all .NET/MAUI code (src/, test/, tools/).

💘 Generated with Crush

Assisted-by: Claude Opus 4.5 via Crush <crush@charm.land>

.crush.json

@@ -0,0 +1,30 @@
+{
+  "$schema": "https://charm.land/crush.json",
+  "permissions": {
+    "allowed_tools": [
+      "view",
+      "ls",
+      "grep",
+      "glob",
+      "edit",
+      "go",
+      "just",
+      "agent",
+      "agentic_fetch"
+    ]
+  },
+  "options": {
+    "initialize_as": "AGENTS.md",
+    "skills_paths": ["./.agents/skills"]
+  },
+  "lsp": {
+    "typescript": {
+      "command": "typescript-language-server",
+      "args": ["--stdio"]
+    },
+    "omnisharp": {
+      "command": "wsl",
+      "args": ["--", "bash", "-lc", "\"OmniSharp\""]
+    }
+  }
+}