Repository-Specific Configuration (.git-commit-summary.yaml / project config)

Problem Statement

Currently, git-commit-summary loads configuration exclusively from global/XDG locations (~/.config/git-commit-summary/config.env) and local .env files in the working directory root. It does not support repository-specific configuration files (e.g., .git-commit-summary.yaml or project-level .env/config files) that can be checked into version control.

Proposed Feature: Repository-Specific Configuration

Allow individual Git repositories to define their own commit standards, prompts, LLM model preferences, and exclusion rules directly inside the repository.

Detailed Outline Plan

1. Config Discovery & Precedence:

   • Extend internal/config to search for a repository-specific configuration file (e.g., .git-commit-summary.yaml or .git-commit-summary.env) in the current working directory or repository root (walking up to the git worktree root).
   • Establish clear configuration precedence:
     1. CLI flags / environment variables (highest priority)
     2. Repository-specific config (.git-commit-summary.yaml / .env in repo root)
     3. User local .env file
     4. XDG global configuration (~/.config/git-commit-summary/config.env) (lowest priority)

2. Schema & Fields:

   • Support project-level settings such as:
     • Preferred LLM provider and model (LLM_PROVIDER, GEMINI_MODEL, etc.)
     • Custom system prompt or prompt template path
     • Additional project-specific file exclusions or overrides

3. Testing & Validation:

   • Add unit tests in internal/config verifying correct configuration merging and precedence order when repository configs are present.

Start by reading the existing configuration loading code and tests under internal/config to understand global/XDG and local .env behavior. Trace how the current working directory and Git worktree are identified, then define the repository-config format and precedence from the issue. Done means repository-specific settings merge correctly and internal/config tests cover discovery, merging, and precedence.