feat: add Atlas Terminal — Next.js 14 + FastAPI full-stack migration

Complete migration from Streamlit to Next.js 14 App Router + FastAPI backend.

Frontend (Next.js 14):
- 10 pages: Overview, Research, Valuation, Technical, Markets, Earnings, News, Portfolio, Filings, Settings
- Terminal Noir dark theme with custom Tailwind config
- TradingView Lightweight Charts for candlestick/volume
- Valuation: DCF, Sensitivity Matrix, Monte Carlo, Tornado, Reverse DCF
- Financial Statements table with YoY growth badges and margin rows
- SEC EDGAR inline filing viewer with section tabs
- News split-view with iframe article embedding
- Technical Analysis with RSI, MACD, Bollinger, Fibonacci, Moving Averages
- Earnings beat/miss visualization
- AI Copilot chat panel with Gemini integration

Backend (FastAPI):
- 13 routers: market_data, financials, valuation, technical, earnings, insider, edgar, news, portfolio, analysis, chat, estimates, fx
- Services: DCF engine, Monte Carlo simulation, sensitivity analysis, risk metrics, SEC parser, technical indicators
- yfinance + yahooquery data sources with fallback pattern
- SQLite caching layer

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

atlas-terminal/server/models/db.py

@@ -0,0 +1,22 @@
+"""Supabase database client for ATLAS Terminal."""
+import os
+from typing import Optional
+
+# Supabase client (lazy init)
+_supabase_client = None
+
+def get_supabase():
+    """Get or create Supabase client. Returns None if not configured."""
+    global _supabase_client
+    if _supabase_client is not None:
+        return _supabase_client
+    url = os.environ.get("SUPABASE_URL")
+    key = os.environ.get("SUPABASE_KEY")
+    if not url or not key:
+        return None
+    try:
+        from supabase import create_client
+        _supabase_client = create_client(url, key)
+        return _supabase_client
+    except ImportError:
+        return None