Function emit_flow_facts 

pub fn emit_flow_facts<I, N>(
    store: &mut FactStore,
    prov: &FactProvenance,
    unit_logical_id: &str,
    flows: I,
) -> usize
where
    I: IntoIterator<Item = (N, ValueFlow)>,
    N: Into<String>,

Emit flow-lattice facts from explicit (name, ValueFlow) rows.

The name is trimmed and upper-cased before fact emission, so whitespace/comment-only source changes that preserve semantic identity keep stable fact IDs.