Item 18: course SVG corpus → O2 flat-vector (mobile legibility floor 74/80 → 0) + blocking gate

.okf/build/test-gates.md

@@ -179,12 +179,14 @@ extend it when adding components or critical files. The macOS full suite remains
   the repo - fresh clones had a hooksPath pointing at nothing. Adding any
   root dotfile/dot-dir? Check `git check-ignore -v <path>` before assuming
   it's tracked.
-- REPORT-ONLY build gates (each flips to blocking once its backlog hits
-  zero via an env flag): `bin/check-svg-floor` (`SVG_FLOOR_BLOCK=1`)
-  catches course SVGs whose smallest text renders <9px@390;
-  `bin/check-course-paths` (`COURSE_PATH_BLOCK=1`) catches lesson
-  `Next:`/branch drift vs `data/course_sequence.yaml`. Both are standalone
-  (NOT yet wired into hugo-build/CI), carry a `--self-test`, and print a
-  burn-down list + exit 0 until their env flag is set. (A landing-parity
-  variant was tried and dropped as redundant - YAGNI: a report-only gate
-  nobody wires in earns its keep only when it guards an active backlog.)
+- Build gates that started report-only and flip to blocking once their
+  backlog hits zero: `bin/check-svg-floor` catches course SVGs whose
+  smallest text renders <9px@390 - **now BLOCKING** (2026-08-12, item18
+  cleared the whole 80-SVG corpus to O2 flat-vector): `bin/hugo-build`
+  runs it with `SVG_FLOOR_BLOCK=1` and fails the build on any regression;
+  run bare for a report-only burn-down. `bin/check-course-paths`
+  (`COURSE_PATH_BLOCK=1`) catches lesson `Next:`/branch drift vs
+  `data/course_sequence.yaml` - still standalone/report-only (its backlog
+  isn't zero yet). Both carry a `--self-test`. (A landing-parity variant
+  was tried and dropped as redundant - YAGNI: a report-only gate nobody
+  wires in earns its keep only when it guards an active backlog.)

.okf/log.md

@@ -1,5 +1,17 @@
 # Bundle Update Log
 
+## 2026-08-12 (item18) - course SVG corpus → O2, check-svg-floor now blocking
+
+* **Update**: item18 converted the entire course exhibit-SVG corpus to O2
+  flat-vector (74/80 under the 9px@390 mobile floor → 0) across 4 sub-waves.
+  `bin/check-svg-floor` **flipped from report-only to BLOCKING**: `bin/hugo-build`
+  now runs it with `SVG_FLOOR_BLOCK=1` and fails the build on any regression.
+  `.okf/build/test-gates.md` updated to reflect the flip.
+* **Pattern**: "fix the gate, not the instance" completed - the report-only net
+  that enumerated the backlog (SW-1..SW-4) is now the guard, so the defect
+  can't silently return. The pixel suite masks `<img>` SVGs, so this build gate
+  + rendered review are the only real coverage for exhibit legibility.
+
 ## 2026-08-12 (item16 landing migration) - below-fold coverage gap confirmed
 
 * **Update**: `.okf/build/test-gates.md` documents the REPORT-ONLY build-gate

bin/check-svg-floor

@@ -10,9 +10,10 @@
 #   => font_viewBox >= 9 * viewBox_width / 390
 #
 # Usage: bin/check-svg-floor [dir]   (default: content/course)
-# Report-only today (exit 0 with a burn-down list) because ~55 not-yet-converted
-# reference/continuation SVGs still fail. Flip REPORT_ONLY=false to make it a
-# blocking gate once the whole course is converted.
+# BLOCKING since 2026-08-12: item18 converted the whole course SVG corpus to O2
+# flat-vector (74/80 under-floor → 0), so bin/hugo-build now runs this with
+# SVG_FLOOR_BLOCK=1 and fails the build on any regression. Run bare (no env
+# flag) for a report-only burn-down list.
 
 REPORT_ONLY = ENV.fetch("SVG_FLOOR_BLOCK", "") != "1"
 FLOOR_PX = 9.0

bin/hugo-build

@@ -44,6 +44,17 @@ if [ -f "$SCRIPT_DIR/validate-course" ]; then
   fi
 fi
 
+# Course exhibit SVGs must clear the 9px@390 mobile legibility floor.
+# Blocking since 2026-08-12 (item18 cleared the whole corpus to O2 flat-vector).
+if [ -f "$SCRIPT_DIR/check-svg-floor" ]; then
+  if ! SVG_FLOOR_BLOCK=1 "$SCRIPT_DIR/check-svg-floor"; then
+    echo ""
+    echo "❌ An exhibit SVG renders below the 9px@390 floor. Redraw it to the"
+    echo "   O2 spec (viewBox W=720, min font >=17) - see .okf/design/house-visual-spec.md."
+    exit 1
+  fi
+fi
+
 HUGO_ARGS=(hugo build --noBuildLock --environment "$ENVIRONMENT" --destination "$OUTPUT_DIR")
 [ -n "$BASE_URL" ] && HUGO_ARGS+=(--baseURL "$BASE_URL")
 [ -n "$BUILD_DRAFTS" ] && HUGO_ARGS+=(--buildDrafts)