Bump version to 4.0.1 with Web UI improvements

- Update version to 4.0.1 across constants.py, __init__.py, pyproject.toml, README
- Refactor channel key UI from radio buttons to select dropdown
- Add LED indicator and key capsule CSS styles
- Reorganize encode/decode forms: RSA key section moved up, PIN + Channel in row
- Streamline channel key JavaScript for dropdown-based selection

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

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

src/stegasoo/__init__.py

@@ -1,5 +1,5 @@
 """
-Stegasoo - Secure Steganography with Multi-Factor Authentication (v4.0.0)
+Stegasoo - Secure Steganography with Multi-Factor Authentication (v4.0.1)
 
 Changes in v4.0.0:
 - Added channel key support for deployment/group isolation
@@ -7,11 +7,11 @@ Changes in v4.0.0:
 - encode() and decode() now accept channel_key parameter
 """
 
-__version__ = "4.0.0"
+__version__ = "4.0.1"
 
 # Core functionality
 from .encode import encode
-from .decode import decode, decode_file
+from .decode import decode, decode_file, decode_text
 
 # Credential generation
 from .generate import (
@@ -153,11 +153,12 @@ DCT_BYTES_PER_PIXEL = 0.125
 __all__ = [
     # Version
     "__version__",
-    
+
     # Core
     "encode",
     "decode",
     "decode_file",
+    "decode_text",
     
     # Generation
     "generate_pin",

src/stegasoo/constants.py

@@ -1,5 +1,5 @@
 """
-Stegasoo Constants and Configuration (v4.0.0 - Channel Key Support)
+Stegasoo Constants and Configuration (v4.0.1 - Channel Key Support)
 
 Central location for all magic numbers, limits, and crypto parameters.
 All version numbers, limits, and configuration values should be defined here.
@@ -21,7 +21,7 @@ from pathlib import Path
 # VERSION
 # ============================================================================
 
-__version__ = "4.0.0"
+__version__ = "4.0.1"
 
 # ============================================================================
 # FILE FORMAT

src/stegasoo/crypto.py

@@ -624,12 +624,15 @@ def get_active_channel_key() -> Optional[str]:
     return get_channel_key()
 
 
-def get_channel_fingerprint() -> Optional[str]:
+def get_channel_fingerprint(key: Optional[str] = None) -> Optional[str]:
     """
-    Get a display-safe fingerprint of the configured channel key.
-    
+    Get a display-safe fingerprint of a channel key.
+
+    Args:
+        key: Channel key (if None, uses configured key)
+
     Returns:
         Masked key like "ABCD-••••-••••-••••-••••-••••-••••-3456" or None
     """
     from .channel import get_channel_fingerprint as _get_fingerprint
-    return _get_fingerprint()
+    return _get_fingerprint(key)

src/stegasoo/steganography.py

@@ -56,23 +56,24 @@ EXT_TO_FORMAT = {
 }
 
 # =============================================================================
-# OVERHEAD CONSTANTS (v3.2.0 - Updated for date-independent format)
+# OVERHEAD CONSTANTS (v4.0.0 - Updated for channel key support)
 # =============================================================================
-# v3.2.0 Header format (no date field):
+# v4.0.0 Header format (with flags byte for channel key indicator):
 #   Magic:   4 bytes  (\x89ST3)
-#   Version: 1 byte   (4 for v3.2.0)
+#   Version: 1 byte   (5 for v4.0.0)
+#   Flags:   1 byte   (bit 0 = has channel key)
 #   Salt:    32 bytes
 #   IV:      12 bytes
 #   Tag:     16 bytes
 #   -----------------
-#   Total:   65 bytes
+#   Total:   66 bytes
 #
-# Previous v3.1.0 had date field (10 bytes + 1 byte length) = 76 bytes header
-# The old value of 104 was incorrect even for v3.1.0
+# v3.2.0 had 65 bytes (no flags byte)
+# v3.1.0 had date field (10 bytes + 1 byte length) = 76 bytes header
 
-HEADER_OVERHEAD = 65       # v3.2.0: Magic + version + salt + iv + tag
+HEADER_OVERHEAD = 66       # v4.0.0: Magic + version + flags + salt + iv + tag
 LENGTH_PREFIX = 4          # 4 bytes for payload length in LSB embedding
-ENCRYPTION_OVERHEAD = HEADER_OVERHEAD + LENGTH_PREFIX  # 69 bytes total
+ENCRYPTION_OVERHEAD = HEADER_OVERHEAD + LENGTH_PREFIX  # 70 bytes total
 
 # DCT output format options (v3.0.1)
 DCT_OUTPUT_PNG = 'png'