Merge gh/main (b574c6eb) into adr009/delivery

# Conflicts:
#	Cargo.nix
#	scripts/build-doc-site.mjs

scripts/build-doc-site.mjs

@@ -70,6 +70,7 @@ const SECTIONS = [
       ["context/code/numtower.md", "code/numtower", "numtower, the numeric tower"],
       ["context/code/zset.md", "code/zset", "zset, the Z-set group"],
       ["context/code/delivery.md", "code/delivery", "delivery, notices and corrections"],
+      ["context/code/improvise-incremental.md", "code/improvise-incremental", "improvise-incremental, the plug"],
       ["context/code/kb-tool.md", "code/kb-tool", "The kb tool"],
       ["context/code/tooling.md", "code/tooling", "The repository's own checkers"],
     ],
@@ -91,6 +92,7 @@ const SECTIONS = [
       ["context/test-evidence/numtower.md", "test-evidence/numtower", "numtower"],
       ["context/test-evidence/zset.md", "test-evidence/zset", "zset"],
       ["context/test-evidence/delivery.md", "test-evidence/delivery", "delivery"],
+      ["context/test-evidence/improvise-incremental.md", "test-evidence/improvise-incremental", "improvise-incremental"],
       ["context/test-evidence/tooling.md", "test-evidence/tooling", "The repository's own gates"],
       ["context/test-evidence/layout-cost.md", "test-evidence/layout-cost", "Layout and keypress cost"],
       ["context/test-evidence/scale-bisect.md", "test-evidence/scale-bisect", "Scale bisect"],