Plugin = {
  name        = "Inject Header",
  description = [[
Inject custom headers into every intercepted request.

**Config** (YAML):
```yaml
headers:
  - "X-My-Header: myvalue"
```
  ]],
  on_request  = { sync = true },
}

local headers = {}

function on_config()
  headers = {}
  local cfg = get_config()
  if cfg and cfg.headers then
    for _, line in ipairs(cfg.headers) do
      local name, value = line:match("^([^:]+):%s*(.+)$")
      if name and value then
        table.insert(headers, { name = name, value = value })
      end
    end
  end
end

function on_request(req)
  for _, h in ipairs(headers) do
    req:set_header(h.name, h.value)
  end
end