feat: add devcontainer configuration for consistent development environment

.devcontainer/Dockerfile

@@ -0,0 +1,27 @@
+FROM mcr.microsoft.com/devcontainers/python:1-3.12
+
+# Install system dependencies
+RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+    && apt-get -y install --no-install-recommends \
+        net-tools \
+        iputils-ping \
+        traceroute \
+        dnsutils \
+        curl \
+        git \
+    && apt-get clean -y && rm -rf /var/lib/apt/lists/*
+
+# Install uv for fast dependency management
+RUN pip install --upgrade pip uv
+
+# Set working directory
+WORKDIR /workspace
+
+# Copy project files
+COPY . .
+
+# Install dependencies
+RUN uv pip install -e .[dev]
+
+# Default command
+CMD ["bash"]

.devcontainer/devcontainer.json

@@ -0,0 +1,36 @@
+{
+  "name": "Netsleuth Development",
+  "build": {
+    "dockerfile": "Dockerfile"
+  },
+  "features": {
+    "ghcr.io/devcontainers/features/git:1": {},
+    "ghcr.io/devcontainers/features/github-cli:1": {}
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "ms-python.python",
+        "ms-python.vscode-pylance",
+        "charliermarsh.ruff",
+        "ms-python.mypy-type-checker",
+        "tamasfe.even-better-toml",
+        "GitHub.copilot-chat"
+      ],
+      "settings": {
+        "python.defaultInterpreterPath": "/usr/local/bin/python",
+        "python.linting.enabled": true,
+        "python.linting.ruffEnabled": true,
+        "python.linting.mypyEnabled": true,
+        "python.formatting.provider": "black",
+        "editor.formatOnSave": true,
+        "editor.codeActionsOnSave": {
+          "source.organizeImports": "explicit"
+        }
+      }
+    }
+  },
+  "forwardPorts": [8000],
+  "postCreateCommand": "uv pip install -e .[dev]",
+  "remoteUser": "root"
+}