ci: enable CodeQL + add code-scanning badge

.github/workflows/codeql.yml

@@ -0,0 +1,36 @@
+name: CodeQL
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+  schedule:
+    - cron: '22 4 * * 1'
+  workflow_dispatch:
+
+permissions:
+  security-events: write
+  contents: read
+
+jobs:
+  analyze:
+    name: Analyze (Rust)
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      contents: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@db488ddef3bf6cb639b32c2e9a7c0a7ea8271d28 # v4
+        with:
+          languages: rust
+
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@db488ddef3bf6cb639b32c2e9a7c0a7ea8271d28 # v4
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@db488ddef3bf6cb639b32c2e9a7c0a7ea8271d28 # v4

README.md

@@ -1,6 +1,6 @@
 # MT5-Quant
 
-[![OpenSSF Scorecard](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/masdevid/mt5-quant/badges/badge.json)](https://scorecard.dev/viewer/?uri=github.com/masdevid/mt5-quant) [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/14227/badge)](https://bestpractices.coreinfrastructure.org/projects/14227) [![Rust CI](https://github.com/masdevid/mt5-quant/actions/workflows/rust.yml/badge.svg)](https://github.com/masdevid/mt5-quant/actions/workflows/rust.yml) [![crates.io](https://img.shields.io/crates/v/mt5-quant.svg)](https://crates.io/crates/mt5-quant) [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)
+[![OpenSSF Scorecard](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/masdevid/mt5-quant/badges/badge.json)](https://scorecard.dev/viewer/?uri=github.com/masdevid/mt5-quant) [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/14227/badge)](https://bestpractices.coreinfrastructure.org/projects/14227) [![Rust CI](https://github.com/masdevid/mt5-quant/actions/workflows/rust.yml/badge.svg)](https://github.com/masdevid/mt5-quant/actions/workflows/rust.yml) [![crates.io](https://img.shields.io/crates/v/mt5-quant.svg)](https://crates.io/crates/mt5-quant) [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE) [![CodeQL](https://img.shields.io/badge/CodeQL-enabled-brightgreen)](https://github.com/masdevid/mt5-quant/security/code-scanning)
 
 **MCP server for MT5 strategy development on macOS/Linux.** 89 tools to compile, backtest, analyze, optimize, debug crashes, and manage MQL5 Expert Advisors — no Windows required.