Prune non-canonical instruction marker files even when asset exists (#48 review)

Codex PR review (should): instruction prune が tool 単位 all-or-nothing で、instruction
asset があると instructions/* スキャンを丸ごとスキップしていた。canonical な
INSTRUCTION_FILENAMES だけを保持し、それ以外の marker 付きファイルは asset 有無に
かかわらず削除するようにした。回帰 self-test を追加。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: kosako

scripts/lib/build.rb

@@ -171,11 +171,12 @@ def prune
           end
         end
 
-        # instruction: その tool 向け instruction asset が無ければ generated を削除する。
-        next if instruction_expected[tool]
-
+        # instruction: 期待する canonical ファイル (INSTRUCTION_FILENAMES) 以外の
+        # marker 付きファイルを削除する。instruction asset が無ければ canonical も対象。
+        keep = instruction_expected[tool] ? ArtifactTargets::INSTRUCTION_FILENAMES[tool] : nil
         Dir.glob(File.join(@root, "generated", tool, "instructions", "*")).sort.each do |file|
           next unless File.file?(file)
+          next if keep && File.basename(file) == keep
 
           if InstructionMarker.parse(File.read(file))
             FileUtils.rm_f(file)

scripts/tests/build-test.sh

@@ -245,6 +245,32 @@ grep -q "pruned: generated/codex/instructions/AGENTS.md" "$tmp/out-iprune" || fa
 [ ! -e "$tmp/instr/generated/codex/instructions/AGENTS.md" ] || fail "orphan instruction should be removed"
 [ ! -e "$tmp/instr/generated/claude-code/instructions/CLAUDE.md" ] || fail "orphan claude instruction should be removed"
 
+# --- case 4e: instruction asset があっても canonical 以外の marker ファイルは prune ---
+mkdir -p "$tmp/instr3/shared/instructions"
+cat > "$tmp/instr3/shared/instructions/personal-ops.md" <<'EOF'
+# ops
+EOF
+cat > "$tmp/instr3/shared/instructions/personal-ops.asset.yml" <<'EOF'
+schema_version: 1
+name: personal-ops
+kind: instruction
+visibility: public
+targets:
+  - codex
+risk:
+  prompt_injection: low
+  privacy: low
+source:
+  path: shared/instructions/personal-ops.md
+  format: markdown
+EOF
+"$build" --root "$tmp/instr3" --quiet > /dev/null
+printf '<!-- agent-tools:managed v=1 repo=agent-tools name=personal-old target=codex artifact_kind=instruction source=shared/x.md build_id=sha256:old -->\nstale\n' \
+  > "$tmp/instr3/generated/codex/instructions/STRAY.md"
+"$build" --root "$tmp/instr3" --prune > "$tmp/out-stray" 2>&1 || fail "prune should pass: $(cat "$tmp/out-stray")"
+[ -f "$tmp/instr3/generated/codex/instructions/AGENTS.md" ] || fail "canonical instruction must survive prune"
+[ ! -e "$tmp/instr3/generated/codex/instructions/STRAY.md" ] || fail "non-canonical marker file should be pruned"
+
 # --- case 5: repository 本体が build できる ---
 repo_root=$(CDPATH= cd -- "$script_dir/../.." && pwd)
 "$build" --root "$repo_root" --quiet > "$tmp/out-repo" 2>&1 \