Add VITE_PROXY_TARGET to the example environment file and use it in
the Vite dev proxy configuration with a localhost fallback. Expand the
LLM development guide with env file loading order, version-control
rules, and variable descriptions. Also clean up ignored local tool
paths in .gitignore and remove duplicated README env examples.chore: document env files and configure proxy target
Add VITE_PROXY_TARGET to the example environment file and use it in
the Vite dev proxy configuration with a localhost fallback. Expand the
LLM development guide with env file loading order, version-control
rules, and variable descriptions. Also clean up ignored local tool
paths in .gitignore and remove duplicated README env examples.
skytek_xinliang