Add Admin Recovery System with multiple backup options

- Recovery key generation (32-char alphanumeric, dashed format)
- Multiple backup methods: text file, QR code, stego image
- QR codes obfuscated with XOR (RECOVERY_OBFUSCATION_KEY constant)
- Stego backup hides key in image using Stegasoo itself
- CLI: `stegasoo admin recover --db path/to/db`
- Web routes: /recover, /account/recovery/regenerate
- Toast notifications now auto-dismiss after 20s with fade
- Updated WEB_UI.md and CLI.md documentation for v4.1.0

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "stegasoo"
-version = "4.0.1"
+version = "4.1.0"
 description = "Secure steganography with hybrid photo + passphrase + PIN authentication"
 readme = "README.md"
 license = "MIT"