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/append_row.py

@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+"""
+append_row.py — append one expense row to the configured Google Sheet.
+
+Reads config from ../config.json.
+Reads a single JSON object from stdin. Keys (all optional; missing -> ""):
+    date, merchant, category, amount, currency,
+    amount_hkd, fx_rate, fx_date, payment_method,
+    line_items, raw_ocr, note, receipt
+
+`logged_at` is set automatically to now (UTC, ISO-8601).
+
+Prints the updated range on success; exits non-zero on failure.
+"""
+from __future__ import annotations
+
+import json
+import os
+import sys
+from datetime import datetime, timezone
+from pathlib import Path
+
+from google.oauth2.service_account import Credentials
+from googleapiclient.discovery import build
+
+
+CONFIG_PATH = Path(__file__).resolve().parent.parent / "config.json"
+
+COLUMNS = [
+    "date", "merchant", "category", "amount", "currency",
+    "amount_hkd", "fx_rate", "fx_date", "payment_method",
+    "line_items", "raw_ocr", "note", "receipt", "logged_at",
+]
+
+
+def load_config() -> dict:
+    if not CONFIG_PATH.exists():
+        sys.exit(
+            f"config.json not found at {CONFIG_PATH}. "
+            f"Copy config.example.json to config.json and fill it in."
+        )
+    cfg = json.loads(CONFIG_PATH.read_text())
+    cfg["service_account_path"] = os.path.expanduser(cfg["service_account_path"])
+    return cfg
+
+
+def main() -> int:
+    cfg = load_config()
+    row = json.loads(sys.stdin.read())
+    row.setdefault(
+        "logged_at",
+        datetime.now(timezone.utc).isoformat(timespec="seconds"),
+    )
+
+    values = [str(row.get(col, "")) for col in COLUMNS]
+
+    creds = Credentials.from_service_account_file(
+        cfg["service_account_path"],
+        scopes=["https://www.googleapis.com/auth/spreadsheets"],
+    )
+    svc = build("sheets", "v4", credentials=creds, cache_discovery=False)
+    resp = (
+        svc.spreadsheets()
+        .values()
+        .append(
+            spreadsheetId=cfg["sheet_id"],
+            range=f"{cfg['worksheet']}!A1",
+            valueInputOption="USER_ENTERED",
+            insertDataOption="INSERT_ROWS",
+            body={"values": [values]},
+        )
+        .execute()
+    )
+    updated = resp.get("updates", {}).get("updatedRange", "?")
+    print(f"OK {updated}")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())