v4.0.2: Add Web UI authentication and optional HTTPS

- Add single-admin login with SQLite3 user storage
- First-run setup wizard for admin account creation
- Account management page for password changes
- Optional HTTPS with auto-generated self-signed certificates
- Configurable via STEGASOO_AUTH_ENABLED, STEGASOO_HTTPS_ENABLED env vars
- UI improvements: larger QR previews, consistent panel styling
- Update docker-compose.yml with auth config and persistent volumes
- Update all documentation for v4.0.2

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

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

src/stegasoo/constants.py

@@ -1,9 +1,14 @@
 """
-Stegasoo Constants and Configuration (v4.0.1 - Channel Key Support)
+Stegasoo Constants and Configuration (v4.0.2 - Web UI Authentication)
 
 Central location for all magic numbers, limits, and crypto parameters.
 All version numbers, limits, and configuration values should be defined here.
 
+CHANGES in v4.0.2:
+- Added Web UI authentication with SQLite3 user storage
+- Added optional HTTPS with auto-generated self-signed certificates
+- UI improvements for QR preview panels and PIN/channel columns
+
 BREAKING CHANGES in v4.0.0:
 - Added channel key support for deployment/group isolation
 - FORMAT_VERSION bumped to 5 (adds flags byte to header)
@@ -20,7 +25,7 @@ from pathlib import Path
 # VERSION
 # ============================================================================
 
-__version__ = "4.0.1"
+__version__ = "4.0.2"
 
 # ============================================================================
 # FILE FORMAT