bug: vector-db and llm-summary should not be default features

[aphoristicartist]

Context

PR #242 adds vector-db and llm-summary to default features in cli/Cargo.toml:

default = ["document", "vector-db", "llm-summary"]

This pulls in candle-nn, ONNX runtime, reqwest, tokio full runtime, hf-hub for every cargo install infiniloom.

Impact

• Massive binary size increase
• Significant compile time increase
• May fail on platforms without native deps (ONNX)
• Users who don't need semantic search pay the full cost

Suggested Fix

Remove from default features. Keep as opt-in. The existing full feature can include them.

Files

• cli/Cargo.toml
• engine/Cargo.toml

Severity

Critical

Found during review of #242