fix(docker): COPY alert_rules.yaml 進容器

規則引擎從 ./alert_rules.yaml 載入，Dockerfile 漏了 COPY
2026-04-09 ogt: fix

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

apps/api/Dockerfile

@@ -53,6 +53,8 @@ COPY --from=builder /usr/local/bin /usr/local/bin
 ARG CACHE_BUST=none
 COPY apps/api/src/ ./src/
 COPY apps/api/models.json ./models.json
+# 2026-04-09 ogt: 規則引擎配置 — alert_rule_engine.py 從此檔載入規則
+COPY apps/api/alert_rules.yaml ./alert_rules.yaml
 
 # Create non-root user
 RUN useradd -m -u 1000 appuser && chown -R appuser:appuser /app