feat(nofxi): proactive intelligence - Sentinel, Brain, Learner

🧠 Brain (proactive intelligence):
- Receives signals from Sentinel and decides when to notify
- Signal debouncing (same type+symbol within 10min)
- Morning brief at 08:30, evening brief at 20:30 (AI-generated)
- Crypto news scanning every 5 minutes
- Auto-filters high-impact news by sentiment + relevance

👁️ Sentinel (market anomaly detection):
- Watches BTC/ETH/SOL by default (expandable)
- Price breakout detection (>3% in 5 minutes)
- Volume spike detection (>3x average)
- Funding rate anomaly detection (>0.1%)
- 60-second scan interval, 1-hour price history buffer

📰 News Monitor:
- CryptoCompare API (free, no auth)
- Keyword-based sentiment classification (bullish/bearish/neutral)
- Symbol extraction from headlines
- Deduplication via seen URLs

📚 Learner (trading memory):
- User profile analysis (win rate, preferred side, risk tolerance)
- Trading lessons storage (win/loss patterns, strategy notes)
- AI prediction tracking (log predictions → resolve with actual P/L)
- Prediction accuracy metrics per model

NOFXi is no longer a passive chatbot. It watches, thinks, learns, and acts.

nofxi/internal/perception/news.go

@@ -0,0 +1,136 @@
+package perception
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// NewsItem represents a crypto news headline.
+type NewsItem struct {
+	Title     string    `json:"title"`
+	Source    string    `json:"source"`
+	URL       string    `json:"url"`
+	Sentiment string    `json:"sentiment"` // "bullish", "bearish", "neutral"
+	Symbols   []string  `json:"symbols"`   // Related symbols
+	Timestamp time.Time `json:"timestamp"`
+}
+
+// NewsMonitor fetches crypto news and detects sentiment shifts.
+type NewsMonitor struct {
+	httpClient *http.Client
+	logger     *slog.Logger
+	lastCheck  time.Time
+	seenURLs   map[string]bool
+}
+
+// NewNewsMonitor creates a new news monitor.
+func NewNewsMonitor(logger *slog.Logger) *NewsMonitor {
+	return &NewsMonitor{
+		httpClient: &http.Client{Timeout: 15 * time.Second},
+		logger:     logger,
+		seenURLs:   make(map[string]bool),
+	}
+}
+
+// FetchNews gets recent crypto news from CryptoCompare (free, no auth needed).
+func (n *NewsMonitor) FetchNews() ([]NewsItem, error) {
+	url := "https://min-api.cryptocompare.com/data/v2/news/?lang=EN&sortOrder=latest"
+	resp, err := n.httpClient.Get(url)
+	if err != nil {
+		return nil, fmt.Errorf("fetch news: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var result struct {
+		Data []struct {
+			Title      string `json:"title"`
+			Source     string `json:"source"`
+			URL        string `json:"url"`
+			Body       string `json:"body"`
+			Categories string `json:"categories"`
+			PublishedOn int64  `json:"published_on"`
+		} `json:"Data"`
+	}
+	if err := json.Unmarshal(body, &result); err != nil {
+		return nil, fmt.Errorf("parse news: %w", err)
+	}
+
+	var items []NewsItem
+	for _, d := range result.Data {
+		if n.seenURLs[d.URL] {
+			continue
+		}
+		n.seenURLs[d.URL] = true
+
+		item := NewsItem{
+			Title:     d.Title,
+			Source:    d.Source,
+			URL:       d.URL,
+			Sentiment: classifySentiment(d.Title + " " + d.Body),
+			Symbols:   extractSymbols(d.Title + " " + d.Categories),
+			Timestamp: time.Unix(d.PublishedOn, 0),
+		}
+		items = append(items, item)
+	}
+
+	// Keep seen URLs map from growing forever
+	if len(n.seenURLs) > 1000 {
+		n.seenURLs = make(map[string]bool)
+	}
+
+	n.lastCheck = time.Now()
+	return items, nil
+}
+
+// classifySentiment does basic keyword-based sentiment analysis.
+func classifySentiment(text string) string {
+	lower := strings.ToLower(text)
+
+	bullish := []string{"surge", "rally", "soar", "bullish", "breakout", "all-time high", "ath",
+		"pump", "moon", "gain", "rise", "uptrend", "buy signal", "accumulate", "adoption"}
+	bearish := []string{"crash", "dump", "plunge", "bearish", "sell-off", "selloff", "decline",
+		"drop", "fall", "liquidat", "hack", "exploit", "ban", "fraud", "scam", "risk"}
+
+	bullCount, bearCount := 0, 0
+	for _, w := range bullish {
+		if strings.Contains(lower, w) {
+			bullCount++
+		}
+	}
+	for _, w := range bearish {
+		if strings.Contains(lower, w) {
+			bearCount++
+		}
+	}
+
+	if bullCount > bearCount {
+		return "bullish"
+	}
+	if bearCount > bullCount {
+		return "bearish"
+	}
+	return "neutral"
+}
+
+// extractSymbols finds crypto symbols mentioned in text.
+func extractSymbols(text string) []string {
+	upper := strings.ToUpper(text)
+	known := []string{"BTC", "ETH", "SOL", "BNB", "XRP", "DOGE", "ADA", "AVAX", "DOT", "LINK", "MATIC", "UNI", "AAVE"}
+	var found []string
+	for _, s := range known {
+		if strings.Contains(upper, s) {
+			found = append(found, s)
+		}
+	}
+	return found
+}