Preserve literal inline comment markers in parsed values

[sricharanreddycheruku]

IniConfig.parse() currently truncates values at any # or ;, including URL fragments and semicolon-separated text. For example, http://example.org/#fragment becomes http://example.org/. Continuation lines have the same problem.

Only recognize an inline comment when its marker is preceded by whitespace, as proposed in #83. Inspect values before stripping leading whitespace so key=#literal stays literal while key= #comment is still an empty value. Apply the same rule to continuation lines and document it in the parsing API and README.

Addresses the inline-comment bug in #83. The malformed section header and broader compatibility-policy questions remain open.

Validation on Linux, Python 3.12:

• The 20 new regression/control cases give 14 failures and 6 passes before the implementation change; all pass afterward.
• Full test suite: 74 passed.
• All configured pre-commit hooks pass: pyproject-fmt, Ruff lint, Ruff format and strict mypy.
• git diff --check passes.

The existing constructor and strip_inline_comments=False behavior are preserved. Section header comment handling is unchanged.

[RonnyPfannschmidt]

closing due to ai violation