v0.4.30

Fixes

• #513 Windows hook null byte warning — hook now skips head -1 for .exe binaries, goes straight to python3 fallback
• #514 to_canvas() hardcoded graphify/obsidian/ path — file refs are now vault-root-relative ({fname}.md), canvas opens correctly regardless of where the vault lives

Tests

• Added test_to_canvas_file_paths_relative_to_vault — would have caught the hardcoded path bug
• Added test_hook_skips_head_on_exe — verifies the Windows fix is present in the hook script