Add repository configuration management with YAML parsing and caching

[Ziinc]

Summary

This PR introduces a repository configuration system that allows projects to define settings via a .treq/config.yaml file. The configuration is parsed, cached in the local SQLite database, and exposed through Tauri commands for the frontend to consume.

Key Changes

• New repo_config module (src-tauri/src/repo_config.rs):
  • Defines RepoConfig struct with optional fields: branch_name_pattern, default_model, default_agent, target_branch, and included_copy_files
  • Implements load_and_cache() to read .treq/config.yaml, parse it with serde_yaml, and cache to the local DB
  • Implements get_cached() to retrieve previously cached configuration without re-reading the file
  • Includes comprehensive test coverage for parsing, caching, and partial configurations
• Database layer enhancements (src-tauri/src/local_db.rs):
  • Added repo_config_cache table to store configuration key-value pairs with timestamps
  • Implemented cache_repo_config() to store individual config fields, replacing stale entries
  • Implemented get_cached_repo_config() to reconstruct the config from cached rows
  • Added clear_db_cache_for_testing() helper for test isolation
  • Includes tests verifying table creation, caching behavior, and stale data cleanup
• Tauri command layer (src-tauri/src/commands/repo_config.rs):
  • Exposed load_repo_yaml_config() command to load and cache config from YAML
  • Exposed get_cached_repo_config() command to retrieve cached config without file I/O
• Module integration:
  • Registered new repo_config module in lib.rs
  • Added repo_config command module to commands/mod.rs
  • Added serde_yaml dependency to Cargo.toml

Implementation Details

• Configuration fields are stored individually in the database, allowing selective queries without full deserialization
• None fields are explicitly deleted from the cache to prevent stale data from persisting across reloads
• The system gracefully handles missing .treq/config.yaml files by returning a default all-None configuration
• Comprehensive test suite covers edge cases including partial configs, cache updates, and round-trip serialization
  https://claude.ai/code/session_01FuRgGXaZYdL4z1bEVVpc5z