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)

addons/saat_invest/models/saham.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+from odoo import api, fields, models
+
+
+class SaatSaham(models.Model):
+    """Master daftar saham / emiten yang dicatat."""
+    _name = 'saat.saham'
+    _description = "Saham / Emiten"
+    _order = 'name'
+
+    name = fields.Char(string="Kode Saham (Ticker)", required=True)
+    perusahaan = fields.Char(string="Nama Perusahaan / Emiten")
+    bursa = fields.Char(string="Bursa", default="IDX")
+    sector = fields.Char(string="Sektor")
+    active = fields.Boolean(string="Aktif", default=True)
+
+    # o2m convenience menampilkan semua transaksi saham ini
+    transaksi_ids = fields.One2many('saat.transaksi', 'saham_id', string="Transaksi")
+
+    _sql_constraints = [
+        ('saham_uniq', 'unique(name)', "Kode saham sudah terdaftar."),
+    ]