feat(规则): 支持同一事件多规则按条件区分并全部发送

Motivation:
止盈、止损等不同策略信号会映射到同一事件（如 trade.close），但原有唯一约束要求每个事件只能有一条规则，无法按策略区分处理。放开该约束后，同一事件可配置多条规则，通过规则条件与精确/通配优先级区分，命中条件的规则全部发送；同时将去重键从消息原文改为信号维度，避免同一信号因时间戳等无关字段差异被误判为重复。

Changes:

* 移除规则 source_id+event 的唯一约束，改为普通索引
* 事件匹配改为返回命中优先级内所有启用规则，并按 ID 逐条派发
* 通知服务遍历多条规则，按条件过滤后聚合发送渠道
* 去重键由消息 body 哈希改为策略/币种/周期/方向/价格信号维度哈希

internal/engine/matcher.go

@@ -2,7 +2,6 @@ package engine
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 
 	"aiaa-notification-service/internal/cache"
@@ -12,59 +11,20 @@ import (
 
 type Matcher struct {
 	store *store.Store
-	cache *cache.Cache
 }
 
-func NewMatcher(s *store.Store, c *cache.Cache) *Matcher {
-	return &Matcher{store: s, cache: c}
+func NewMatcher(s *store.Store, _ *cache.Cache) *Matcher {
+	return &Matcher{store: s}
 }
 
-func (m *Matcher) Match(ctx context.Context, sourceID int, event string) (*model.Rule, error) {
-	// Try cache first
-	if m.cache != nil {
-		cr, err := m.cache.GetRule(ctx, sourceID, event)
-		if err == nil {
-			rule := &model.Rule{ID: cr.RuleID, TemplateID: cr.TemplateID, SourceID: sourceID, Event: event}
-			if cr.Conditions != "" && cr.Conditions != "null" {
-				raw := json.RawMessage(cr.Conditions)
-				rule.Conditions = &raw
-			}
-			return rule, nil
-		}
-	}
-
-	rule, err := m.store.GetRuleBySourceEvent(ctx, sourceID, event)
+func (m *Matcher) Match(ctx context.Context, sourceID int, event string) ([]model.Rule, error) {
+	rules, err := m.store.ListEnabledRulesBySource(ctx, sourceID)
 	if err != nil {
-		rules, listErr := m.store.ListEnabledRulesBySource(ctx, sourceID)
-		if listErr != nil {
-			return nil, fmt.Errorf("match rule: %w", listErr)
-		}
-		picked := PickEventRule(event, rules)
-		if picked == nil {
-			return nil, fmt.Errorf("match rule: %w", err)
-		}
-		return picked, nil
+		return nil, fmt.Errorf("match rule: %w", err)
 	}
-
-	m.warmRuleCache(ctx, sourceID, event, rule)
-	return rule, nil
-}
-
-func (m *Matcher) warmRuleCache(ctx context.Context, sourceID int, event string, rule *model.Rule) {
-	if m.cache == nil {
-		return
-	}
-	tmpl, err := m.store.GetTemplate(ctx, rule.TemplateID)
-	if err != nil {
-		return
-	}
-	cr := &cache.CachedRule{
-		RuleID:     rule.ID,
-		TemplateID: rule.TemplateID,
-		Content:    tmpl.Content,
-	}
-	if rule.Conditions != nil {
-		cr.Conditions = string(*rule.Conditions)
-	}
-	_ = m.cache.SetRule(ctx, sourceID, event, cr)
+	picked := PickEventRules(event, rules)
+	if len(picked) == 0 {
+		return nil, fmt.Errorf("match rule: no rule for source %d event %s", sourceID, event)
+	}
+	return picked, nil
 }