feat: add ccr activate command for Agent SDK integration

[d-kimuson]

Background

I'm the author of d-kimuson/claude-code-viewer, which uses the Agent SDK to provide a web-based GUI for Claude Code. I received this issue from a user who wanted to use it with claude-code-router.

After reading the implementation, I realized it should work in principle by running ccr start and setting the appropriate environment variables. However, manually converting the config file to environment variables is cumbersome. I thought it would be beneficial to have a CLI command that just handles the environment variable setup. This would enable seamless integration not only with claude-code-viewer but with any Agent SDK-based application.

Implementation

This PR adds a ccr activate command to achieve this goal. This is also a proof of concept - if a different interface design is preferred, feel free to reject this and recreate it, or let me know and I can make the changes.

Usage

Basic Usage

$ ccr activate
export ANTHROPIC_AUTH_TOKEN="test"
export ANTHROPIC_API_KEY=""
export ANTHROPIC_BASE_URL="http://127.0.0.1:3456"
export NO_PROXY="127.0.0.1"
export DISABLE_TELEMETRY="true"
export DISABLE_COST_WARNINGS="true"
export API_TIMEOUT_MS="600000"
unset CLAUDE_CODE_USE_BEDROCK

$ eval $(ccr activate)

$ echo $ANTHROPIC_AUTH_TOKEN
test

With Agent SDK Applications

# Start the router
ccr start

# Activate environment variables
eval $(ccr activate)

# Now any Agent SDK application will use ccr's routing
npx @kimuson/claude-code-viewer@latest
# or any other Agent SDK application

Technical Details

• Refactored environment variable creation logic from ccr code into a shared createEnvVariables() function
• The activate command outputs in shell-friendly format by default (no --shell flag needed)
• Environment variables match exactly what ccr code uses internally
• Updated both English and Chinese documentation

Testing

Tested on my local environment:

• ccr activate outputs correct environment variables ✅
• eval $(ccr activate) successfully sets environment variables ✅
• ccr code still works correctly with refactored code ✅

[d-kimuson]

related: #855