fix(ci): satisfy rustfmt and clippy after bin+lib split

The Rust workflow lint job failed on master:
- cargo fmt --check: imports in src/main.rs were misordered
  (mcp_server/models/pipeline lines out of alphabetical order,
  McpError/McpRequest/McpResponse tuple unsorted) from b843146.
- cargo clippy -D warnings: clippy::new_without_default now fires on
  DealAnalyzer, ReportExtractor, OptimizationParser, StageExecutor
  and McpServer because the lib target (src/lib.rs) makes their
  pub constructors part of the public API.

Fix: reorder main.rs imports per rustfmt; add Default impls
delegating to new() for the five types.

src/analytics/analyze.rs

@@ -7,6 +7,12 @@ use crate::models::metrics::Metrics;
 
 pub struct DealAnalyzer;
 
+impl Default for DealAnalyzer {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl DealAnalyzer {
     pub fn new() -> Self {
         Self

src/analytics/extract.rs

@@ -8,6 +8,12 @@ use crate::models::{Deal, Metrics};
 
 pub struct ReportExtractor;
 
+impl Default for ReportExtractor {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl ReportExtractor {
     pub fn new() -> Self {
         Self

src/main.rs

@@ -7,10 +7,10 @@ use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
 use tokio::net::TcpListener;
 use tracing::{error, info};
 
+use mt5_quant::mcp_server::{McpServer, Notification};
 use mt5_quant::models::Config;
 use mt5_quant::pipeline::backtest::{BacktestParams, BacktestPipeline};
-use mt5_quant::mcp_server::{McpServer, Notification};
-use mt5_quant::{McpRequest, McpResponse, McpError};
+use mt5_quant::{McpError, McpRequest, McpResponse};
 
 #[derive(Parser)]
 #[command(name = "mt5-quant")]

src/mcp_server.rs

@@ -31,6 +31,12 @@ pub struct McpServer {
     notification_tx: Arc<Mutex<Option<mpsc::UnboundedSender<Notification>>>>,
 }
 
+impl Default for McpServer {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl McpServer {
     pub fn new() -> Self {
         let config = ModelsConfig::load().unwrap_or_default();

src/optimization/parser.rs

@@ -17,6 +17,12 @@ pub struct OptimizationPass {
 
 pub struct OptimizationParser;
 
+impl Default for OptimizationParser {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl OptimizationParser {
     pub fn new() -> Self {
         Self

src/pipeline/stages.rs

@@ -40,6 +40,13 @@ impl Stage {
 #[allow(dead_code)]
 pub struct StageExecutor;
 
+#[allow(dead_code)]
+impl Default for StageExecutor {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 #[allow(dead_code)]
 impl StageExecutor {
     pub fn new() -> Self {