Resolve Issue #4229: "Author not detected in C++ file".

[AdityaOP007]

Fix author detection when "Author:" tag lacks trailing space (Issue #4229)
[
Input-
from cluecode.copyrights import detect_copyrights_from_lines
lines = [
(1, '// Date:9 April,2012'),
(2, '// Author:Frankie.Chu'),
(3, '// IDE Arduino-1.0')
]
results = list(detect_copyrights_from_lines(lines))
for r in results:
print(f'- {r.author} (Found on line {r.start_line})')

output-
Input Lines:
[(1, '// Date:9 April,2012'), (2, '// Author:Frankie.Chu'), (3, '// IDE Arduino-1.0')]
Detected Authors:

• Frankie.Chu (Found on line 2)
  ]

Changes made by Aditya regarding to Author detection (Issue #4229):

1. Token Normalization (src/cluecode/copyrights.py):

   • Added a normalize_author_colon regex hook in the prepare_text_line pipeline to identify "Author:" or "author:" tags that are not immediately followed by whitespace.
   • Automatically injects a space to ensure Author:Name becomes Author: Name, allowing the tokenization engine to correctly isolate the author keyword from the name.

2. Lexer enhancements (src/cluecode/copyrights.py):

   • Added a new grammar lexer rule (r'^[A-Z][a-z]+\.[A-Z][a-z]+$', 'NAME').
   • Correctly identifies Name.Name handle structures (like Frankie.Chu) as proper NAME entities instead of generic nouns (NN), allowing the existing NLP author detection grammar to successfully extract them.

3. Testing (tests/cluecode/test_copyrights_basic.py & tests/cluecode/data/authors/):

   • Added basic tokenization tests to verify prepare_text_line correctly normalizes spacing after colons without breaking existing correct formats.
   • Added a data-driven test (author_no_space_after_colon.cpp and its YAML) mimicking the exact reported edge-case to prevent future regressions.