feat: implement automated payment inference and sync to Google Sheets

CLAUDE.md

@@ -21,10 +21,26 @@ This project uses a hybrid workflow:
 
 ## When Code Exists
 
-Once a tech stack is chosen and implementation begins, update this file with:
-- Build, test, and lint commands
-- Architecture overview
-- Development setup instructions
+## Development Setup
+
+This project uses `uv` for dependency management.
+
+```bash
+uv venv          # Create virtual environment
+uv sync          # Install dependencies from pyproject.toml
+source .venv/bin/activate
+```
+
+Alternatively, use the Makefile:
+- `make sync`      - Sync bank transactions to Google Sheets
+- `make infer`     - Automatically infer Person/Purpose/Amount in the sheet
+- `make reconcile` - Generate balance report from Google Sheets data
+- `make fees`      - Calculate expected fees from attendance
+- `make match`     - (Legacy) Match bank data directly
+- `make web`       - Start dashboard
+- `make image`     - Build Docker image
+
+Requires `credentials.json` in the root for Google Sheets API access.
 
 ## Git Commits