feat: Add devcontainer configuration for n8n-workflows development

- Configure Claude Code optimized devcontainer with Python support
- Add Python development tools (black, flake8, isort) to Dockerfile
- Include VS Code extensions for Python and workflow development
- Add firewall script for secure development environment
- Update .gitignore to exclude Claude Code local settings

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.devcontainer/devcontainer.json

@@ -0,0 +1,62 @@
+{
+  "name": "n8n Workflows - Claude Code",
+  "build": {
+    "dockerfile": "Dockerfile",
+    "args": {
+      "TZ": "${localEnv:TZ:America/Los_Angeles}"
+    }
+  },
+  "runArgs": [
+    "--cap-add=NET_ADMIN",
+    "--cap-add=NET_RAW"
+  ],
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "dbaeumer.vscode-eslint",
+        "esbenp.prettier-vscode",
+        "eamodio.gitlens",
+        "ms-python.python",
+        "ms-python.flake8",
+        "ms-python.black-formatter",
+        "tamasfe.even-better-toml"
+      ],
+      "settings": {
+        "editor.formatOnSave": true,
+        "editor.defaultFormatter": "esbenp.prettier-vscode",
+        "editor.codeActionsOnSave": {
+          "source.fixAll.eslint": "explicit"
+        },
+        "python.defaultInterpreterPath": "/usr/local/bin/python3",
+        "python.linting.enabled": true,
+        "python.linting.flake8Enabled": true,
+        "[python]": {
+          "editor.defaultFormatter": "ms-python.black-formatter"
+        },
+        "terminal.integrated.defaultProfile.linux": "zsh",
+        "terminal.integrated.profiles.linux": {
+          "bash": {
+            "path": "bash",
+            "icon": "terminal-bash"
+          },
+          "zsh": {
+            "path": "zsh"
+          }
+        }
+      }
+    }
+  },
+  "remoteUser": "node",
+  "mounts": [
+    "source=claude-code-bashhistory,target=/commandhistory,type=volume",
+    "source=claude-code-config,target=/home/node/.claude,type=volume"
+  ],
+  "remoteEnv": {
+    "NODE_OPTIONS": "--max-old-space-size=4096",
+    "CLAUDE_CONFIG_DIR": "/home/node/.claude",
+    "POWERLEVEL9K_DISABLE_GITSTATUS": "true"
+  },
+  "workspaceMount": "source=${localWorkspaceFolder},target=/workspace,type=bind,consistency=delegated",
+  "workspaceFolder": "/workspace",
+  "postCreateCommand": "sudo /usr/local/bin/init-firewall.sh"
+}