diff --git a/package.json b/package.json
index b8b09baf..a80d30fe 100644
--- a/package.json
+++ b/package.json
@@ -25,14 +25,9 @@
     "contracts/schema",
     "contracts/spec",
     "tools",
-    "tools/cli/psp-toolchain.json",
     "hosts/web",
     "assets/brand",
     "assets/fonts",
-    "engine/backends/esp32p4-ppa/src",
-    "engine/backends/esp32p4-ppa/Cargo.toml",
-    "engine/backends/esp32p4-ppa/Cargo.lock",
-    "engine/backends/esp32p4-ppa/README.md",
     "engine/core/src",
     "engine/core/Cargo.toml",
     "engine/wasm/src",
diff --git a/tests/npm-package.test.ts b/tests/npm-package.test.ts
index 10d8b7d4..1edeaa8d 100644
--- a/tests/npm-package.test.ts
+++ b/tests/npm-package.test.ts
@@ -20,6 +20,55 @@ function packedFiles(cwd: string): string[] {
 }
 
 describe("published npm artifacts", () => {
+  // The files map is a governed surface, not a mirror of the repo tree: an
+  // entry ships ONLY when the framework runtime, the compiler, the shipped
+  // tools, or a `pocket` CLI target consumes it from the tarball. Rust
+  // sources ride along solely as build inputs for CLI-buildable targets
+  // (psp, vita, the web/sim wasm) plus the deliberately standalone Pocket3D
+  // Vita crate pair for out-of-tree Vita 3D apps. Platform source
+  // integrations without a CLI target (e.g. the ESP32-P4 PPA backend, whose
+  // ESP-IDF C component cannot ship in npm anyway) stay git-only. Adding an
+  // entry here means updating this list in the same PR — deliberately.
+  test("the files map stays exactly the governed surface", async () => {
+    const manifest = await Bun.file(`${root}package.json`).json();
+    expect(manifest.files).toEqual([
+      "framework/src",
+      "framework/compiler",
+      "contracts/schema",
+      "contracts/spec",
+      "tools",
+      "hosts/web",
+      "assets/brand",
+      "assets/fonts",
+      "engine/core/src",
+      "engine/core/Cargo.toml",
+      "engine/wasm/src",
+      "engine/wasm/Cargo.toml",
+      "hosts/psp/src",
+      "hosts/psp/targets",
+      "hosts/psp/build.rs",
+      "hosts/psp/Cargo.toml",
+      "hosts/psp/Cargo.lock",
+      "hosts/vita/.cargo",
+      "hosts/vita/assets",
+      "hosts/vita/src",
+      "hosts/vita/build.rs",
+      "hosts/vita/Cargo.toml",
+      "hosts/vita/Cargo.lock",
+      "hosts/vita/README.md",
+      "hosts/vita/rust-toolchain.toml",
+      "engine/pocket3d/crates/pocket3d-vita/src",
+      "engine/pocket3d/crates/pocket3d-vita/examples",
+      "engine/pocket3d/crates/pocket3d-vita/Cargo.toml",
+      "engine/pocket3d/crates/pocket3d-vita/Cargo.lock",
+      "engine/pocket3d/crates/pocket3d-bsp/Cargo.toml",
+      "engine/pocket3d/crates/pocket3d-bsp/src",
+      "pocket.config.ts",
+      "pocket.json",
+      "tsconfig.json",
+    ]);
+  });
+
   test("framework tarball contains every locked native and standalone Pocket3D Vita input", async () => {
     const files = packedFiles(root);
     expect(files).toEqual(expect.arrayContaining([
@@ -38,6 +87,12 @@ describe("published npm artifacts", () => {
       "engine/pocket3d/crates/pocket3d-bsp/src/lib.rs",
     ]));
     expect(files).not.toContain("engine/pocket3d/Cargo.toml");
+    // Git-only platform integrations must not leak into the tarball.
+    expect(files).not.toContain("engine/backends/esp32p4-ppa/src/lib.rs");
+    expect(files.some((file) => file.startsWith("engine/backends/"))).toBe(false);
+    expect(files.some((file) => file.startsWith("hosts/esp32p4/"))).toBe(false);
+    // The CLI toolchain pin still ships via the wholesale "tools" entry.
+    expect(files).toContain("tools/cli/psp-toolchain.json");
 
     const bspManifest = await Bun.file(
       `${root}engine/pocket3d/crates/pocket3d-bsp/Cargo.toml`,