Aplikasi catat jual-beli saham: Odoo 17 + Postgres 16 + addon saat_invest

- docker-compose.yml: odoo:17.0 (port 8069) + postgres:16 (internal, no publish)
- Addon saat_invest: model saat.saham / saat.transaksi / saat.portofolio
  - P/L computed (realized FIFO, unrealized dari harga_sekarang)
  - action_recalculate() endpoint untuk Flutter
  - seed 5 saham IDX (BBRI, TLKM, BBCA, ASII, PTBA)
- JSON-RPC end-to-end terverifikasi: create beli/jual -> recalculate -> portfolio
  (avg_cost 4525, realized 65000, unrealized 220000, nilai 3840000)
- PLAN.md: rancangan disetujui Bozz
- Login Odoo admin/admin (ganti password master di .env, jangan commit)

.gitignore

@@ -0,0 +1,12 @@
+# Rahasia — jangan pernah commit
+.env
+*.local
+.DS_Store
+
+# Python
+__pycache__/
+*.pyc
+
+# Terraform / backup dll
+*.bak
+*.log