feat(extractor): file specific extractor

[danielebriggi]

Add extractor of md frontmatter for metadata

[Copilot]

Pull Request Overview

This PR adds support for extracting metadata from Markdown frontmatter in documents. The implementation introduces a file-specific extractor system that can parse YAML frontmatter from Markdown files and store the extracted metadata separately from the document content.

• Implements a flexible metadata extraction system with base classes and file-specific extractors
• Adds frontmatter extraction for Markdown files using the python-frontmatter library
• Integrates metadata extraction into the document processing pipeline for both new additions and rebuilds

Reviewed Changes

Copilot reviewed 10 out of 12 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/sqlite_rag/extractors/base.py	Defines abstract base class for metadata extractors
src/sqlite_rag/extractors/frontmatter.py	Implements frontmatter extraction for Markdown files
src/sqlite_rag/extractor.py	Main extractor coordinator that selects appropriate extractors by file type
src/sqlite_rag/sqliterag.py	Integrates metadata extraction into document processing pipeline
src/sqlite_rag/reader.py	Adds docstring to parse_file method
src/sqlite_rag/database.py	Fixes import path for sqlite-vector binaries
pyproject.toml	Adds python-frontmatter dependency and removes pytest-cov version pin
tests/	Comprehensive test coverage for all new extraction functionality

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[codecov]

Codecov Report

❌ Patch coverage is 97.43590% with 4 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/sqlite_rag/sqliterag.py	71.42%	3 Missing and 1 partial ⚠️

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