feat: add browser support for provider OAuth in Docker

Docker changes:
- Install Node.js and npm (for Claude CLI)
- Install Firefox ESR for browser-based OAuth
- Install X11 libraries for display forwarding
- Add 'setup' service with display access

Usage:
  xhost +local:docker
  docker-compose run --rm setup
  smarttools providers install

The 'setup' service has DISPLAY and X11 socket access, so browser-based
OAuth flows (Claude, Codex, Gemini, OpenCode) can work inside Docker.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Dockerfile

@@ -11,6 +11,15 @@ LABEL description="SmartTools - Personal AI-powered CLI command builder"
 RUN apt-get update && apt-get install -y --no-install-recommends \
     git \
     curl \
+    # Node.js for Claude CLI
+    nodejs \
+    npm \
+    # Browser for OAuth authentication
+    firefox-esr \
+    # X11 libraries for display
+    libx11-6 \
+    libxext6 \
+    libxrender1 \
     && rm -rf /var/lib/apt/lists/*
 
 # Set working directory

docker-compose.yml

@@ -48,6 +48,26 @@ services:
     stdin_open: true
     tty: true
 
+  # ============================================================================
+  # Setup (with display for browser-based auth)
+  # ============================================================================
+  # Use this for installing providers that need browser authentication
+  # First run: xhost +local:docker
+  setup:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: smarttools:latest
+    environment:
+      - DISPLAY=${DISPLAY:-:0}
+    volumes:
+      - smarttools-data:/root/.smarttools
+      - /tmp/.X11-unix:/tmp/.X11-unix:ro
+    command: ["/bin/bash"]
+    stdin_open: true
+    tty: true
+    network_mode: host
+
 volumes:
   smarttools-data:
     # Persists ~/.smarttools between container runs
@@ -68,3 +88,10 @@ volumes:
 #
 # Interactive shell:
 #   docker-compose run --rm shell
+#
+# Install providers (with browser auth):
+#   xhost +local:docker
+#   docker-compose run --rm setup
+#   # Inside container:
+#   smarttools providers install    # Interactive guide
+#   # Select a provider, it will install and open browser for auth