fix(markdown_normalizer): enhance reliability and code protection

- Fix error fallback mechanism to guarantee 100% rollback to original text on failure
- Improve escape character cleanup to protect inline code blocks from unwanted modification
- Fix 'enable_escape_fix_in_code_blocks' configuration to correctly apply to code blocks when enabled
- Change 'show_debug_log' default to False to reduce console noise and improve privacy
- Update READMEs and docs, bumped version to 1.2.8

tests/plugins/filters/markdown_normalizer/test_reliability.py

@@ -0,0 +1,53 @@
+from plugins.filters.markdown_normalizer.markdown_normalizer import ContentNormalizer, NormalizerConfig
+
+def test_error_rollback():
+    """Issue 57-1: Ensure content is NOT modified if a cleaner raises an exception."""
+    def broken_cleaner(text): raise RuntimeError("Plugin Crash Simulation")
+    config = NormalizerConfig(custom_cleaners=[broken_cleaner])
+    norm = ContentNormalizer(config)
+    raw_text = "Content that should NOT be modified on error."
+    res = norm.normalize(raw_text)
+    assert res == raw_text
+
+def test_inline_code_protection():
+    """Issue 57-2: Protect backslashes inside inline code blocks."""
+    norm = ContentNormalizer(NormalizerConfig(enable_escape_fix=True))
+    inline_code = "Regex: `[\\\\n\\\\r]` and Path: `C:\\\\\\\\Windows` and Normal: \\\\n"
+    res = norm.normalize(inline_code)
+    # The normal \\\\n at the end SHOULD be converted to actual \n
+    # The backslashes inside ` ` should NOT be converted.
+    assert "`[\\\\n\\\\r]`" in res
+    assert "`C:\\\\\\\\Windows`" in res
+    assert "\n" in res
+
+def test_code_block_escape_control():
+    """Issue 57-3: Verify enable_escape_fix_in_code_blocks valve."""
+    # input code: print('\\n')
+    # representation: "print('\\\\n')"
+    block_text = "```python\nprint('\\\\n')\n```"
+    
+    # Subcase A: Disabled (Default)
+    norm_off = ContentNormalizer(NormalizerConfig(enable_escape_fix_in_code_blocks=False))
+    assert norm_off.normalize(block_text) == block_text
+    
+    # Subcase B: Enabled
+    norm_on = ContentNormalizer(NormalizerConfig(enable_escape_fix_in_code_blocks=True))
+    # Expected: "```python\nprint('\n')\n```"
+    res = norm_on.normalize(block_text)
+    assert "\n" in res
+    assert "\\n" not in res.split("```")[1]
+
+def test_latex_protection():
+    """Regression: Ensure LaTeX commands are not corrupted by escape fix."""
+    norm = ContentNormalizer(NormalizerConfig(enable_escape_fix=True))
+    latex_text = "Math: $\\\\times \\\\theta \\\\nu$ and Normal: \\\\n"
+    res = norm.normalize(latex_text)
+    assert "$\\\\times \\\\theta \\\\nu$" in res
+    assert "\n" in res
+
+if __name__ == "__main__":
+    test_error_rollback()
+    test_inline_code_protection()
+    test_code_block_escape_control()
+    test_latex_protection()
+    print("All tests passed!")