feat: Add User-Agent header to CLI API requests for usage tracking #194
Description
Add a User-Agent header (cortexapps-cli/) to all HTTP requests made by CortexClient so CLI usage can be identified and tracked in DataDog.
Motivation
There is currently no way to distinguish CLI-originated API traffic from other sources in DataDog logs.
Approach
- Set User-Agent header on all requests in CortexClient.request()
- Version resolved via importlib.metadata.version()
- Format: cortexapps-cli/ (e.g. cortexapps-cli/1.9.1)
- No server-side changes required — User-Agent is already logged and indexed in DataDog