Feature: Default Evaluation Provider Setup

[kumar-ayan]

Description

Add a first-run setup that asks the user to choose a default evaluation provider (e.g., Ollama, OpenAI, Groq or Gemini). This avoids requiring the --provider flag every time a command is run.

Example First-Run Prompt

No evaluation provider configured.

Select a default provider:

1. Ollama
2. OpenAI
3. Groq
4. Gemini

Behavior

The selected provider should be saved in a config file (e.g. ~/.llmvc/config.json).

Usage

Default usage:
pv eval 23

Override provider when needed:
pv eval 23 --provider openai

Goal

Improve CLI UX by letting users configure a provider once while still allowing overrides.