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/db/pg_cache_repo.py

@@ -0,0 +1,62 @@
+"""
+PostgreSQL cache repository — persistent cache with TTL.
+"""
+import json
+from typing import Optional, Any
+from datetime import datetime, timezone, timedelta
+from server.db.pg_database import get_pg_pool
+
+
+async def pg_cache_get(key: str) -> Optional[Any]:
+    """Get a cached value. Returns None if expired or not found."""
+    pool = await get_pg_pool()
+    if not pool:
+        return None
+    async with pool.acquire() as conn:
+        row = await conn.fetchrow(
+            "SELECT value FROM cache WHERE key = $1 AND expires_at > NOW()",
+            key,
+        )
+        if row and row["value"] is not None:
+            return row["value"]  # JSONB auto-deserializes
+        return None
+
+
+async def pg_cache_set(key: str, value: Any, ttl_seconds: int = 86400) -> None:
+    """Set a cache value with TTL."""
+    pool = await get_pg_pool()
+    if not pool:
+        return
+    expires = datetime.now(timezone.utc) + timedelta(seconds=ttl_seconds)
+    async with pool.acquire() as conn:
+        await conn.execute(
+            """INSERT INTO cache (key, value, expires_at)
+               VALUES ($1, $2::jsonb, $3)
+               ON CONFLICT (key) DO UPDATE SET value = $2::jsonb, expires_at = $3""",
+            key, json.dumps(value), expires,
+        )
+
+
+async def pg_cache_delete(key: str) -> None:
+    """Delete a specific cache entry."""
+    pool = await get_pg_pool()
+    if not pool:
+        return
+    async with pool.acquire() as conn:
+        await conn.execute("DELETE FROM cache WHERE key = $1", key)
+
+
+async def pg_cache_cleanup() -> int:
+    """Remove expired cache entries. Returns count of deleted rows."""
+    pool = await get_pg_pool()
+    if not pool:
+        return 0
+    async with pool.acquire() as conn:
+        result = await conn.execute(
+            "DELETE FROM cache WHERE expires_at < NOW()"
+        )
+        # Parse "DELETE N" result
+        try:
+            return int(result.split()[-1])
+        except (IndexError, ValueError):
+            return 0