feat(webui): trading signal panel, predict-future mode, dark theme & bug fixes

## Summary
Major improvements to the Kronos Web UI focusing on usability, visual clarity,
and a new real-time trading signal analysis panel.

## New Features

### Predict Future Now
- Added a dedicated 'Predict Future Now' button that uses the most recent
  400 candles (lookback) to forecast the next 120 periods beyond the last
  data point — i.e., a true future forecast, not a backtest.
- Future timestamps are generated programmatically via pd.date_range so
  the model always forecasts into the uncharted future.
- No 'actual data' orange trace is shown in this mode (the future hasn't
  happened yet).

### Trading Signal Analysis Panel
- After every prediction a full trading signal panel is displayed below the
  chart, automatically computed from the prediction output.
- Signal categories: STRONG BUY / BUY / NEUTRAL / CAUTION / DO NOT BUY,
  each with a distinct color scheme.
- Panel includes six metric cards: Current Price, Predicted Final Price (%),
  Predicted High, Predicted Low, Predicted Mean, Support / Resistance.
- Trajectory timeline: Now → [Nd: +X%] → [Nd: +X%] → [End: +X%].
- Operations panel: Entry, Stop-Loss (-3%), Target 1, Target 2, Timeframe.

### Dark Theme & Chart Color Overhaul
- Chart background switched to plotly_dark with dark paper/plot bg.
- Historical candles: gray (#78909C / #546E7A) — neutral context.
- Prediction candles: blue (#1E88E5 / #1565C0) — clearly distinguishable.
- Actual/backtest candles: orange (#F57C00 / #BF360C) — easy comparison.

### Windows Launcher (start.ps1)
- One-command launcher: auto-detects the Python installation with CUDA
  support by iterating all python.exe in PATH and testing
  torch.cuda.is_available().
- Falls back to CPU if no CUDA Python is found.
- Deactivates any active venv to prevent using the wrong Python.
- Generates a random port (10000-60000), checks availability via
  Get-NetTCPConnection, then auto-opens the browser after 3 s.
- Supports -SkipInstall flag to skip pip install on repeat launches.

### Data Download Utility (download_data.py)
- CLI utility to download market data (crypto, stocks, forex) via yfinance
  and save to the Kronos data/ directory in the expected CSV format.
- Supports all yfinance intervals (1m, 5m, 15m, 1h, 4h, 1d, 1wk, 1mo).
- Usage: python download_data.py BTC-USD --interval 4h --period 2y

## Bug Fixes

### actual_data showing wrong price range in predict-future mode (critical)
- Root cause: the else branch in the actual_data section always fetched
  df.iloc[0:lookback+pred_len] regardless of mode, so in predict-future
  mode (no start_date) it served the very first candles in the file
  (e.g. 2024 XRP at ~.50 instead of current ~.30), rendering an
  orange trace in a completely wrong price band.
- Fix: actual_data is now mode-aware:
    - predict_future=True  → actual_df = None (no trace)
    - start_date provided  → actual_df from time_range_df[lookback:lookback+pred_len]
    - neither              → no actual data

### historical_start_idx wrong in predict-future mode
- Root cause: historical_start_idx defaulted to 0, so the chart showed
  candles from the very beginning of the file (years-old data) as the
  'historical' context window instead of the last 400 candles.
- Fix: when predict_future=True, historical_start_idx = len(df) - lookback.

## Localization
- All user-visible text translated from Chinese/Portuguese to English.
- html lang attribute updated to 'en'.
- Date formatting locale updated to en-US.
- .gitignore updated to exclude data/ and webui/prediction_results/ (runtime artifacts).

Author: courasneto

.gitignore

@@ -74,3 +74,9 @@ venv.bak/
 temp/
 tmp/
 .python-version
+
+# Market data files (downloaded at runtime)
+data/
+
+# WebUI runtime output
+webui/prediction_results/

download_data.py

@@ -0,0 +1,102 @@
+"""
+Kronos - Downloader de dados de mercado
+Baixa dados de qualquer ativo (cripto, acoes, forex) e salva em data/
+para uso no Web UI.
+
+Uso:
+    python download_data.py XRP-USD        # XRP/USD - diario
+    python download_data.py BTC-USD --interval 1h
+    python download_data.py AAPL --interval 1d --period 2y
+    python download_data.py ETH-USD --interval 5m --period 60d
+    python download_data.py BTC-USD ETH-USD XRP-USD  # multiplos de uma vez
+
+Intervalos suportados: 1m 2m 5m 15m 30m 60m 90m 1h 1d 5d 1wk 1mo
+Periodos suportados  : 1d 5d 1mo 3mo 6mo 1y 2y 5y 10y ytd max
+  (para intervalos < 1h, o maximo e 60 dias)
+"""
+
+import argparse
+import os
+import sys
+import pandas as pd
+import yfinance as yf
+
+DATA_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), "data")
+
+
+def download(ticker: str, interval: str = "1d", period: str = "2y") -> None:
+    print(f"  Baixando {ticker}  intervalo={interval}  periodo={period} ...")
+
+    df = yf.download(ticker, interval=interval, period=period, progress=False, auto_adjust=True)
+
+    if df.empty:
+        print(f"  [ERRO] Nenhum dado retornado para '{ticker}'. Verifique o simbolo.")
+        return
+
+    # Flatten MultiIndex columns (yfinance retorna assim para tickers unicos as vezes)
+    if isinstance(df.columns, pd.MultiIndex):
+        df.columns = [col[0].lower() for col in df.columns]
+    else:
+        df.columns = [c.lower() for c in df.columns]
+
+    # Renomear colunas para o padrao Kronos
+    rename = {"adj close": "close"}
+    df = df.rename(columns=rename)
+
+    # Garantir colunas obrigatorias
+    required = ["open", "high", "low", "close"]
+    missing = [c for c in required if c not in df.columns]
+    if missing:
+        print(f"  [ERRO] Colunas faltando apos download: {missing}. Colunas presentes: {list(df.columns)}")
+        return
+
+    # Resetar index e renomear coluna de data/hora
+    df = df.reset_index()
+    time_col = df.columns[0]          # 'Datetime' ou 'Date'
+    df = df.rename(columns={time_col: "timestamps"})
+    df["timestamps"] = pd.to_datetime(df["timestamps"])
+
+    # Remover timezone para evitar problemas de serializacao
+    if df["timestamps"].dt.tz is not None:
+        df["timestamps"] = df["timestamps"].dt.tz_convert("UTC").dt.tz_localize(None)
+
+    # Manter apenas colunas uteis
+    keep = ["timestamps", "open", "high", "low", "close"]
+    if "volume" in df.columns:
+        keep.append("volume")
+    df = df[keep].dropna()
+
+    # Nome do arquivo: TICKER_interval.csv
+    safe_ticker = ticker.replace("/", "-").replace("=", "")
+    filename = f"{safe_ticker}_{interval}.csv"
+    out_path = os.path.join(DATA_DIR, filename)
+
+    os.makedirs(DATA_DIR, exist_ok=True)
+    df.to_csv(out_path, index=False)
+
+    size_kb = os.path.getsize(out_path) / 1024
+    print(f"  [OK] {filename}  ({len(df)} candles, {size_kb:.1f} KB)  ->  data/{filename}")
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Baixa dados de mercado e salva em data/ para uso no Kronos Web UI."
+    )
+    parser.add_argument("tickers", nargs="+", help="Simbolos yfinance (ex: XRP-USD BTC-USD AAPL)")
+    parser.add_argument("--interval", default="1d",
+                        help="Intervalo das velas (default: 1d). Ex: 5m 1h 1d")
+    parser.add_argument("--period", default="2y",
+                        help="Periodo historico (default: 2y). Ex: 60d 1y 5y max")
+    args = parser.parse_args()
+
+    print(f"\nKronos Data Downloader")
+    print(f"Destino: {DATA_DIR}\n")
+
+    for ticker in args.tickers:
+        download(ticker.upper(), interval=args.interval, period=args.period)
+
+    print(f"\nConcluido! Reinicie o servidor ou recarregue a pagina para ver os novos arquivos.")
+
+
+if __name__ == "__main__":
+    main()

start.ps1

@@ -0,0 +1,104 @@
+# Kronos - Startup Script
+# Starts the Web UI on a random port, using Python with CUDA support
+
+param(
+    [switch]$SkipInstall
+)
+
+$ErrorActionPreference = "Stop"
+
+Write-Host "======================================" -ForegroundColor Cyan
+Write-Host "  Kronos - Startup" -ForegroundColor Cyan
+Write-Host "======================================" -ForegroundColor Cyan
+Write-Host ""
+
+# If a venv is active, deactivate it to avoid using the wrong Python
+if ($env:VIRTUAL_ENV) {
+    Write-Host "[INFO] Deactivating venv '$env:VIRTUAL_ENV' ..." -ForegroundColor Yellow
+    & deactivate 2>$null
+    # Manually clear venv variables from this session's PATH
+    $env:PATH = ($env:PATH -split ';' | Where-Object { $_ -notlike "$env:VIRTUAL_ENV*" }) -join ';'
+    Remove-Item Env:\VIRTUAL_ENV -ErrorAction SilentlyContinue
+    Remove-Item Env:\VIRTUAL_ENV_PROMPT -ErrorAction SilentlyContinue
+}
+
+# Find Python with CUDA support (search all instances in PATH)
+$pythonExe = $null
+$candidatos = (where.exe python 2>$null) -split "`n" | ForEach-Object { $_.Trim() } | Where-Object { $_ -ne "" -and (Test-Path $_) }
+
+foreach ($cand in $candidatos) {
+    $result = & $cand -c "import torch; print(torch.cuda.is_available())" 2>$null
+    if ($result -eq "True") {
+        $pythonExe = $cand
+        break
+    }
+}
+
+if (-not $pythonExe) {
+    # Fallback: accept CPU if no CUDA found
+    $pythonExe = (Get-Command python -ErrorAction SilentlyContinue)?.Source
+    if (-not $pythonExe) {
+        Write-Host "[ERROR] Python not found in PATH. Install Python 3.10+ and try again." -ForegroundColor Red
+        exit 1
+    }
+    Write-Host "[WARNING] Python with CUDA not found. Using CPU: $pythonExe" -ForegroundColor Yellow
+    Write-Host "        Para CUDA, instale: pip install torch --index-url https://download.pytorch.org/whl/cu128" -ForegroundColor Yellow
+} else {
+    $pyVersion = & $pythonExe --version 2>&1
+    $gpuName   = & $pythonExe -c "import torch; print(torch.cuda.get_device_name(0))" 2>&1
+    Write-Host "[OK] $pyVersion  |  CUDA - $gpuName" -ForegroundColor Green
+    Write-Host "[OK] Python: $pythonExe" -ForegroundColor Green
+}
+
+# Project root directory
+$projectRoot = $PSScriptRoot
+Set-Location $projectRoot
+
+# Install dependencies
+if (-not $SkipInstall) {
+    Write-Host "[...] Installing project dependencies ..." -ForegroundColor Yellow
+    & $pythonExe -m pip install -r (Join-Path $projectRoot "requirements.txt") --quiet
+
+    $webuiReqs = Join-Path $projectRoot "webui\requirements.txt"
+    if (Test-Path $webuiReqs) {
+        Write-Host "[...] Installing Web UI dependencies ..." -ForegroundColor Yellow
+        & $pythonExe -m pip install -r $webuiReqs --quiet
+    }
+    Write-Host "[OK] Dependencies installed." -ForegroundColor Green
+} else {
+    Write-Host "[SKIP] Dependency installation skipped (-SkipInstall)." -ForegroundColor Yellow
+}
+
+# Generate random port between 10000 and 60000 (avoids well-known ports)
+$port = Get-Random -Minimum 10000 -Maximum 60000
+for ($i = 0; $i -lt 10; $i++) {
+    if (-not (Get-NetTCPConnection -LocalPort $port -ErrorAction SilentlyContinue)) { break }
+    $port = Get-Random -Minimum 10000 -Maximum 60000
+}
+
+Write-Host ""
+Write-Host "======================================" -ForegroundColor Cyan
+Write-Host "  Kronos Web UI" -ForegroundColor Cyan
+Write-Host "  Port  : $port" -ForegroundColor Cyan
+Write-Host "  URL   : http://localhost:$port" -ForegroundColor Cyan
+Write-Host "======================================" -ForegroundColor Cyan
+Write-Host "Press Ctrl+C to stop the server." -ForegroundColor DarkGray
+Write-Host ""
+
+# Open browser automatically after a few seconds
+Start-Job -ScriptBlock {
+    param($url)
+    Start-Sleep -Seconds 3
+    Start-Process $url
+} -ArgumentList "http://localhost:$port" | Out-Null
+
+# Start Flask on the random port
+Set-Location (Join-Path $projectRoot "webui")
+$env:FLASK_APP = "app.py"
+
+& $pythonExe -c @"
+import sys, os
+sys.path.insert(0, '..')
+from webui.app import app
+app.run(debug=False, host='127.0.0.1', port=$port)
+"@