feat: support run cortex foreground

[luke-nguyen990]

Describe Your Changes

Running Cortex in the foreground provides developers with an additional tool for debugging and helps newcomers learn the flow. This ticket aims to support running Cortex in the foreground without disrupting the current workflow.

cortex start --foreground

Self Checklist

• Added relevant comments, esp in complex areas
• Updated docs (for bug fixes / features)
• Created issues for follow-up changes or refactoring needed

[dan-menlo]

Please update Docs and re-submit PR

• CLI: https://cortex.so/docs/cli/start
• https://cortex.so/docs/basic-usage/

[gabrielle-ong]

@dan-homebrew @luke-nguyen990
This will depends on our decision for #1672

[luke-nguyen990]

@dan-homebrew @luke-nguyen990 This will depends on our decision for #1672

@dan-homebrew @luke-nguyen990 This will depends on our decision for #1672

I want to explore and onboard myself more deeply here.
Before writing the code above, I already looked at the flow for log.

• The current discussion seems to be about the approach and design for log streaming to files.
• For this PR, I created a feature for log in the terminal specifically for optimizing local development, i.e developers can just use a simple cout << for debugging.