row 66 r5: BUILD.md corrects the cap-sentence note, Filbert N2 (#1559)

agents/sage/work/queue-66/BUILD.md

@@ -193,3 +193,8 @@ pi-session.test.mjs, where git now names the context line. Commits 2-7 are `=`.
 0049d05fb585 for the whole diff and d67275ac4251 without `agents/` on both bases. Correction: the r4d note
 above gives 508bb684eade for the whole diff. That number came from e25f76f54 before the 7b9737953 rebase. The
 whole-diff number on r4d is 0049d05fb585. The harness suite runs whole again on this base before landing.
+
+Correction (Filbert round 4 N2, comment 30086): the r4c paragraph says "Row 66's old cap sentence is
+dropped." That's wrong. In round 3's diff the 64 KiB cap sentence is unchanged context, so row 66 never
+wrote it. Row 213 replaced it, and none of row 66's lines were dropped. The landing sessions are in
+LANDING-SESSION.md.