Function run_migrations 

pub async fn run_migrations(config: &Config) -> Result<()>

Run all database migrations.

Creates all tables, indexes, and virtual tables required by Context Harness. Safe to call multiple times — all operations are idempotent.

Tables Created

• documents — normalized document storage
• chunks — text segments with content hashes
• checkpoints — incremental sync cursors
• chunks_fts — FTS5 full-text search index
• embeddings — embedding metadata (model, dims, staleness hash)
• chunk_vectors — embedding vector BLOBs

Errors

Returns an error if the database connection fails or any SQL statement cannot be executed.