feat: Round 5 - Memory Service, Tool Engine, Call Records, Thinking Logs

- Fix: Session history flash (race condition + WS guard)
- Fix: Chat background overlay + sidebar transparency
- Fix: IoT device control (Chinese action names, status field)
- Feat: Independent memory-service (port 8091, 13 endpoints)
- Feat: Independent tool-engine service (port 8092, 13 tools)
- Feat: Tool call logs with paginated DevTools panel
- Feat: Thinking log records with DevTools panel
- Feat: Future development roadmap document
- Chore: Updated .gitignore, go.work, DevTools config
- Chore: 5-service health check, project review docs

backend/tool-engine/Dockerfile

@@ -0,0 +1,19 @@
+# Build stage
+FROM golang:1.24-alpine AS builder
+
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o /tool-engine ./cmd/
+
+# Runtime stage
+FROM alpine:3.21
+
+RUN apk --no-cache add ca-certificates
+WORKDIR /app
+COPY --from=builder /tool-engine .
+
+EXPOSE 8092
+
+ENTRYPOINT ["./tool-engine"]