Initial commit: bookkeeping skill

Receipt-image to Google Sheets expense logger with HKD conversion.
Includes SKILL.md, categories/schema reference, config template,
and Python scripts for FX conversion (frankfurter.app) and Sheets append.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/setup.md

@@ -0,0 +1,39 @@
+# One-time setup
+
+## 1. Python deps
+```
+pip install google-api-python-client google-auth
+```
+
+## 2. Google Cloud service account
+1. Create (or reuse) a GCP project.
+2. Enable the **Google Sheets API** for the project.
+3. Create a **service account**; skip the optional IAM steps.
+4. In the service account, create a **JSON key** and download it.
+5. Move the key to a safe path, e.g. `~/.config/gcp/bookkeeping-sa.json`, then:
+   ```
+   chmod 600 ~/.config/gcp/bookkeeping-sa.json
+   ```
+
+## 3. Prepare the Google Sheet
+1. Create a new Google Sheet (or open an existing one).
+2. Rename the first tab to `Expenses` (or update `worksheet` in config).
+3. In row 1 add headers matching `schema.md` columns A–N:
+   `Date | Merchant | Category | Amount | Currency | Amount (HKD) | FX Rate | FX Date | Payment Method | Line Items | Raw OCR | Note | Receipt | Logged At`
+4. Open the service account JSON and copy the `client_email` value (looks like `...@...iam.gserviceaccount.com`).
+5. Click **Share** on the sheet and add that email as **Editor**.
+6. Copy the sheet ID from the URL: `https://docs.google.com/spreadsheets/d/<SHEET_ID>/edit`.
+
+## 4. Skill config
+```
+cd ~/.claude/skills/bookkeeping
+cp config.example.json config.json
+# edit config.json: sheet_id, service_account_path
+```
+
+## 5. Sanity check
+```
+echo '{"date":"2026-04-20","merchant":"TEST","category":"Other","amount":1,"currency":"HKD","amount_hkd":1,"fx_rate":1,"fx_date":"2026-04-20"}' \
+  | python ~/.claude/skills/bookkeeping/scripts/append_row.py
+```
+You should see `OK Expenses!A2:N2` (or similar) and a new row in the sheet. Delete the TEST row when done.