Add make fast for the quickest local check

Makefile

@@ -1,4 +1,4 @@
-.PHONY: factory-maintain lab next progress prove-homework doctor dev check check-affected prove levels claude smoke hooks eval factory exercise
+.PHONY: fast factory-maintain lab next progress prove-homework doctor dev check check-affected prove levels claude smoke hooks eval factory exercise
 
 doctor:
 	@node -v | grep -qE '^v2[2-9]' && echo "ok node $$(node -v)" || (echo "need Node 22+" && exit 1)
@@ -22,6 +22,12 @@ check:
 check-affected:
 	npx tsx scripts/check-affected.ts $(if $(BASE),--base $(BASE))
 
+# Quickest local read on the first red CI step: lint, types, then only the affected checks. make check stays the gate.
+fast:
+	npm run lint
+	npm run typecheck
+	npx tsx scripts/check-affected.ts --base origin/main
+
 prove:
 	npm run prove -- $(LEVEL)
 

levels.json

@@ -168,6 +168,7 @@
     "scripts/impact.ts",
     "scripts/impact.test.ts",
     "scripts/check-affected.ts",
+    "scripts/fast.test.ts",
     "tests/structure/impact.test.ts",
     "scripts/dependencies.ts",
     "tests/structure/dependency-drift.test.ts",

scripts/fast.test.ts

@@ -0,0 +1,38 @@
+import { readFileSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+
+const makefile = readFileSync("Makefile", "utf8");
+
+// The tab-indented lines of one target's recipe.
+function recipe(target: string): string[] {
+  const lines = makefile.split("\n");
+  const start = lines.indexOf(`${target}:`);
+  if (start < 0) return [];
+  const body: string[] = [];
+  for (const line of lines.slice(start + 1)) {
+    if (!line.startsWith("\t")) break;
+    body.push(line.trim());
+  }
+  return body;
+}
+
+describe("make fast", () => {
+  it("is declared phony", () => {
+    const phony = makefile.split("\n").find((l) => l.startsWith(".PHONY:")) ?? "";
+    expect(phony.split(/\s+/)).toContain("fast");
+  });
+
+  it("runs lint, typecheck, then the affected checks against origin/main", () => {
+    expect(recipe("fast")).toEqual([
+      "npm run lint",
+      "npm run typecheck",
+      "npx tsx scripts/check-affected.ts --base origin/main",
+    ]);
+  });
+
+  it("is not called from check, which stays the gate", () => {
+    const check = recipe("check");
+    expect(check.length).toBeGreaterThan(0);
+    expect(check.join("\n")).not.toMatch(/\bfast\b/);
+  });
+});