Refactor CLI into package

[adrianwedd]

Move ollama_search_cli.py into atlas_cli/ package and prepare for Typer-based subcommands.

Task ID: CLI-001

Component: CLI

Epic: DX Improvement

Actionable Steps

• Create atlas_cli/init.py and atlas_cli/main.py

• Wrap existing search logic using Typer

• Update README usage examples

Acceptance Criteria

• python -m atlas_cli search llama works

• Unit test covers basic command