fix: Update YAML frontmatter tag formatting for Obsidian compatibility (#280)

Signed-off-by: Drew Cain <groksrc@users.noreply.github.com>
Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: Paul Hernandez <phernandez@users.noreply.github.com>
Co-authored-by: Paul Hernandez <60959+phernandez@users.noreply.github.com>

src/basic_memory/markdown/markdown_processor.py

@@ -7,6 +7,7 @@ from frontmatter import Post
 from loguru import logger
 
 from basic_memory import file_utils
+from basic_memory.file_utils import dump_frontmatter
 from basic_memory.markdown.entity_parser import EntityParser
 from basic_memory.markdown.schemas import EntityMarkdown, Observation, Relation
 
@@ -115,7 +116,7 @@ class MarkdownProcessor:
 
         # Create Post object for frontmatter
         post = Post(content, **frontmatter_dict)
-        final_content = frontmatter.dumps(post, sort_keys=False)
+        final_content = dump_frontmatter(post)
 
         logger.debug(f"writing file {path} with content:\n{final_content}")