feat: native linux-x64-glibc module packages and reviewed license supplements (ADR 0049, ADR 0052)

Implements ADR 0049's deferred native target and ADR 0052's reviewed
license supplements. The proof case is a real module using sharp.
packageFormat stays 1, and `any` is unchanged.

Packager (@ekklesia/module-pack):
- --target linux-x64-glibc. Native or platform-specific packages, found by
  the same generic rule that refuses them in `any`, stay outside the bundle.
- Each native package's production closure is walked through its own
  dependencies, installed optionalDependencies that match the target, and
  required peers. It is copied as real files flat under node_modules/<name>,
  with no links, dev dependencies, declarations, source maps, or other
  platforms' packages. Missing or foreign-platform required dependencies,
  version conflicts, links, foreign machines, and Node.js range conflicts
  fail closed.
- runtime.nodeApi, nodeAbi, and libcVersion are read from the binaries by a
  small ELF reader: the addon's node_api_module_get_api_version_v1 and the
  newest GLIBC_ symbol version needed. No shelling out. A native target with
  no addon is refused.
- ADR 0052 supplements: package-provided material stays primary. An exact
  match on name, version, and ekklesia-content-v1 digest (sorted normalized
  paths with each file's size and SHA-256; no metadata) adds labelled
  material after the package's own. Any mismatch, a declared-licence
  conflict, or a malformed or unreviewed supplement file fails. Missing
  material with no supplement still fails.

Supplement for @img/[email protected]:
- 184 components and 143 unique texts, assembled from the exact upstream
  sources sharp-libvips v1.3.3 builds linux-x64 from: 27 C/C++ libraries,
  glib's gvdb, librsvg's Rust crates (reproduced with cargo tree), the Rust
  standard library at the rustc commit recorded in the binary, plus the
  LGPL-3.0, GPL-3.0, and MPL-2.0 texts. Each source is recorded with its
  SHA-256 in PROVENANCE.md.
- It pins digest ekklesia-content-v1:sha256:50647b0b…, which is identical
  from the installed copy and from the registry tarball.
- LGPL/MPL source-availability determinations stay open, as ADR 0052
  states. Nothing claims they are met.

Verifier (Core):
- linux-x64-glibc is accepted only on a host whose platform, arch, glibc
  family and version, and Node-API version (from Node itself) match.
- Every ELF file must be x86-64; every .node must be an ELF object.
- `any` packages now also refuse node_modules/ and ELF files.
- Contract: native metadata must state nodeApi or nodeAbi, and Linux targets
  libcVersion (ADR 0049).

Proof:
- A checked-in AGPL native fixture packs byte-identically from unrelated
  copies (8.86 MB) and verifies with Core's verifier.
- Extracted elsewhere, it runs a sharp resize and PNG round trip in an
  empty-environment process. Every resolution stays in the package, and
  only the package's addon and libvips plus host system libraries load.

Signage is untouched.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

core/src/modules/index.ts

@@ -9,6 +9,7 @@ export * from "./lifecycle-schema.js";
 export * from "./lifecycle-store.js";
 export * from "./migration-discovery.js";
 export * from "./modules-directory.js";
+export * from "./module-package-host.js";
 export * from "./module-package-verification.js";
 export * from "./permissions.js";
 export * from "./realtime.js";

core/src/modules/module-package-host.ts

@@ -0,0 +1,59 @@
+/**
+ * The facts about this host that decide whether a native Module Package v1 can run on it
+ * (ADR 0049): operating system, CPU, C library family and version, and Node-API version.
+ *
+ * Everything comes from Node.js itself (`process.platform`, `process.arch`, `process.versions`, and
+ * the diagnostic report's `glibcVersionRuntime`), never from running a system command. A fact Node
+ * cannot report is left undefined, and every check that needs it fails closed.
+ */
+export interface ModulePackageHost {
+  readonly platform: string;
+  readonly arch: string;
+  /** The C library on Linux: glibc with its runtime version, or undefined when it cannot be proven
+   * to be glibc (musl reports none). */
+  readonly libc?: { readonly family: "glibc"; readonly version: string };
+  /** `process.versions.napi`: the highest Node-API version this Node.js provides. */
+  readonly nodeApi?: number;
+  /** `process.versions.modules`: the ABI an ABI-specific addon must have been built for. */
+  readonly nodeAbi?: string;
+}
+
+function glibcVersion(): string | undefined {
+  try {
+    const header = (process.report?.getReport() as { header?: { glibcVersionRuntime?: unknown } })
+      ?.header;
+    const version = header?.glibcVersionRuntime;
+    return typeof version === "string" && /^\d+\.\d+(?:\.\d+)?$/u.test(version)
+      ? version
+      : undefined;
+  } catch {
+    return undefined;
+  }
+}
+
+export function currentModulePackageHost(): ModulePackageHost {
+  const libc = process.platform === "linux" ? glibcVersion() : undefined;
+  const nodeApi = Number(process.versions.napi);
+  return Object.freeze({
+    arch: process.arch,
+    ...(libc === undefined
+      ? {}
+      : { libc: Object.freeze({ family: "glibc" as const, version: libc }) }),
+    ...(Number.isInteger(nodeApi) && nodeApi > 0 ? { nodeApi } : {}),
+    ...(typeof process.versions.modules === "string" ? { nodeAbi: process.versions.modules } : {}),
+    platform: process.platform,
+  });
+}
+
+/** The native targets this platform can verify, with what each requires of a host. */
+export const MODULE_PACKAGE_NATIVE_TARGETS: ReadonlyMap<
+  string,
+  {
+    readonly platform: string;
+    readonly arch: string;
+    readonly libc: "glibc";
+    readonly elfMachine: number;
+  }
+> = new Map([
+  ["linux-x64-glibc", { arch: "x64", elfMachine: 62, libc: "glibc", platform: "linux" }],
+]);

core/src/modules/module-package-verification.ts

@@ -18,6 +18,11 @@ import {
   safeParseModulePackageRuntimePackage,
 } from "@ekklesia/contracts/module-package";
 import { discoverModules, MODULE_MANIFEST_FILENAME, ModuleDiscoveryError } from "./discovery.js";
+import {
+  currentModulePackageHost,
+  MODULE_PACKAGE_NATIVE_TARGETS,
+  type ModulePackageHost,
+} from "./module-package-host.js";
 import { discoverModuleMigrations, ModuleMigrationDiscoveryError } from "./migration-discovery.js";
 import {
   type ModulePackageArchive,
@@ -56,11 +61,14 @@ export type ModulePackageVerificationErrorCode =
   | "MODULE_PACKAGE_FILE_UNLISTED"
   | "MODULE_PACKAGE_FORMAT_UNSUPPORTED"
   | "MODULE_PACKAGE_IDENTITY_MISMATCH"
+  | "MODULE_PACKAGE_LIBC_INCOMPATIBLE"
   | "MODULE_PACKAGE_MANIFEST_INVALID"
   | "MODULE_PACKAGE_METADATA_INVALID"
   | "MODULE_PACKAGE_METADATA_MISSING"
   | "MODULE_PACKAGE_MODULE_INVALID"
   | "MODULE_PACKAGE_NATIVE_FILE"
+  | "MODULE_PACKAGE_NATIVE_FILE_INCOMPATIBLE"
+  | "MODULE_PACKAGE_NODE_API_INCOMPATIBLE"
   | "MODULE_PACKAGE_RUNTIME_INCOMPATIBLE"
   | "MODULE_PACKAGE_RUNTIME_PACKAGE_INVALID"
   | "MODULE_PACKAGE_SDK_INCOMPATIBLE"
@@ -85,12 +93,19 @@ const messages: Readonly<Record<ModulePackageVerificationErrorCode, string>> = O
     "The package metadata, runtime package.json, and manifest disagree about the module's identity.",
   MODULE_PACKAGE_LAYOUT_INVALID:
     "The archive must contain exactly one top-level module directory, with each path once.",
+  MODULE_PACKAGE_LIBC_INCOMPATIBLE:
+    "The package needs a newer C library than this host provides, or one it cannot establish.",
   MODULE_PACKAGE_LINK: "The archive contains a link; module packages may contain none.",
   MODULE_PACKAGE_MANIFEST_INVALID: "The package's module manifest is missing or invalid.",
   MODULE_PACKAGE_METADATA_INVALID: "The package metadata is invalid.",
   MODULE_PACKAGE_METADATA_MISSING: "The archive contains no package metadata.",
   MODULE_PACKAGE_MODULE_INVALID: "The packaged module failed module validation.",
-  MODULE_PACKAGE_NATIVE_FILE: "An any-target package contains a native file.",
+  MODULE_PACKAGE_NATIVE_FILE:
+    "An any-target package contains a native file or a node_modules directory.",
+  MODULE_PACKAGE_NATIVE_FILE_INCOMPATIBLE:
+    "A native file in the package is not built for the package's target.",
+  MODULE_PACKAGE_NODE_API_INCOMPATIBLE:
+    "The package's addons need a Node-API version or Node.js ABI this host does not provide.",
   MODULE_PACKAGE_RUNTIME_INCOMPATIBLE:
     "The package needs a Node.js version this host does not run.",
   MODULE_PACKAGE_RUNTIME_PACKAGE_INVALID:
@@ -131,6 +146,8 @@ export interface ModulePackagePlatform {
   readonly databaseRuntime: Readonly<Record<string, string>>;
   /** Defaults to the running process's Node.js version. */
   readonly nodeVersion?: string;
+  /** Defaults to this process's own host (`currentModulePackageHost`). */
+  readonly host?: ModulePackageHost;
 }
 
 export interface VerifyModulePackageOptions {
@@ -266,12 +283,19 @@ function checkCompatibility(
   files: ReadonlyMap<string, Buffer>,
   platform: ModulePackagePlatform,
 ): void {
-  // This verifier implements the portable target only. Native targets are a later slice.
-  if (metadata.target !== MODULE_PACKAGE_ANY_TARGET) {
-    fail("MODULE_PACKAGE_TARGET_INCOMPATIBLE");
-  }
-  if ([...files.keys()].some((filePath) => filePath.toLowerCase().endsWith(".node"))) {
-    fail("MODULE_PACKAGE_NATIVE_FILE");
+  if (metadata.target === MODULE_PACKAGE_ANY_TARGET) {
+    // An any-target package bundles everything: no addon, no ELF object, no node_modules.
+    for (const [filePath, data] of files) {
+      if (
+        filePath.toLowerCase().endsWith(".node") ||
+        filePath.startsWith("node_modules/") ||
+        isElf(data)
+      ) {
+        fail("MODULE_PACKAGE_NATIVE_FILE");
+      }
+    }
+  } else {
+    checkNativeTarget(metadata, files, platform.host ?? currentModulePackageHost());
   }
   if (!isVersionCompatible(platform.nodeVersion ?? process.versions.node, metadata.runtime.node)) {
     fail("MODULE_PACKAGE_RUNTIME_INCOMPATIBLE");
@@ -296,6 +320,74 @@ function checkCompatibility(
   }
 }
 
+function isElf(data: Uint8Array): boolean {
+  return (
+    data.length >= 4 && data[0] === 0x7f && data[1] === 0x45 && data[2] === 0x4c && data[3] === 0x46
+  );
+}
+
+/** `2.41` → `2.41.0`, for comparison against a semantic-version range. */
+function asSemver(version: string): string {
+  const parts = version.split(".");
+  return [...parts, "0", "0"].slice(0, 3).join(".");
+}
+
+/**
+ * A native target (ADR 0049): accepted only for a target this platform implements, on a host that
+ * provably matches it. Platform, CPU, C library family and minimum version, and the Node-API version
+ * or ABI the addons need are all checked; a fact the host cannot establish fails closed. Every ELF
+ * object in the package must be built for the target's machine, and every `.node` addon must be one.
+ */
+function checkNativeTarget(
+  metadata: ModulePackageMetadata,
+  files: ReadonlyMap<string, Buffer>,
+  host: ModulePackageHost,
+): void {
+  const target = MODULE_PACKAGE_NATIVE_TARGETS.get(metadata.target);
+  if (
+    target === undefined ||
+    host.platform !== target.platform ||
+    host.arch !== target.arch ||
+    host.libc?.family !== target.libc
+  ) {
+    fail("MODULE_PACKAGE_TARGET_INCOMPATIBLE");
+  }
+  const required = metadata.runtime.libcVersion;
+  if (
+    required === undefined ||
+    host.libc === undefined ||
+    !isVersionCompatible(asSemver(host.libc.version), required)
+  ) {
+    fail("MODULE_PACKAGE_LIBC_INCOMPATIBLE");
+  }
+  const { nodeAbi, nodeApi } = metadata.runtime;
+  if (
+    (nodeApi === undefined && nodeAbi === undefined) ||
+    (nodeApi !== undefined && (host.nodeApi === undefined || host.nodeApi < nodeApi)) ||
+    (nodeAbi !== undefined && host.nodeAbi !== nodeAbi)
+  ) {
+    fail("MODULE_PACKAGE_NODE_API_INCOMPATIBLE");
+  }
+  for (const [filePath, data] of files) {
+    const addon = filePath.toLowerCase().endsWith(".node");
+    if (!isElf(data)) {
+      if (addon) {
+        fail("MODULE_PACKAGE_NATIVE_FILE_INCOMPATIBLE");
+      }
+      continue;
+    }
+    // ELF64, little-endian, for the target's machine (e_machine at offset 18).
+    if (
+      data.length < 20 ||
+      data[4] !== 2 ||
+      data[5] !== 1 ||
+      data.readUInt16LE(18) !== target.elfMachine
+    ) {
+      fail("MODULE_PACKAGE_NATIVE_FILE_INCOMPATIBLE");
+    }
+  }
+}
+
 /** Writes the archive's directories (`0755`) and files (`0644`) under `root`, which must not exist.
  * Safe by construction: every path was validated as relative and non-escaping, and only directories
  * and regular files exist. Ownership is the writing process's, never the archive's. */