style(io): keep the new comment inside the two-line cap

The comment added with the previous commit ran to three lines and
scripts/check-comment-runs.py failed the `test` job on it. The reason it was not
caught locally is worth recording: --check-evidence is ADDITIVE, so the run does
answer the cap, but the output was read through `tail -1` and the cap's line is
the FIRST of the two. A gate filtered down to the line you expect is not a gate.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FC2jVn8Au7E9JPkw6bwXXH

crates/improvise-io/src/import/wizard.rs

@@ -199,9 +199,8 @@ impl ImportPipeline {
             if let Value::Object(map) = record {
                 let mut coords: Vec<(String, String)> = vec![];
                 let mut missing: Option<usize> = None;
-                // Charged to the tally only once this record survives the walk:
-                // a row dropped for a LATER missing category never lands, so
-                // counting it would make the warning depend on category order.
+                // Charged only once this record survives the walk: a row dropped
+                // for a LATER missing category never lands (context/test-evidence).
                 let mut unparsed_here: Vec<usize> = vec![];
 
                 for (cat_idx, cat_proposal) in categories.iter().enumerate() {