feat: Module Package v1 carries the module's own license (ADR 0051)

Every Module Package v1 now declares the module's license and carries its
text. packageFormat stays 1; pre-ADR-0051 metadata fails closed.

- Contracts: ekklesia.package.json requires an SPDX `license` expression,
  validated with spdx-expression-parse, with UNLICENSED and non-expressions
  refused. The `files` list must hold exactly one non-empty root LICENSE.
  The package contracts move to the @ekklesia/contracts/module-package
  subpath, so the SPDX parser and its data (spdx-exceptions and
  spdx-license-ids ship no licence files) never reach a module bundle
  through the SDK's re-export of the contracts root.
- Packager: reads the source package.json's string SPDX declaration and
  never invents one. It requires an explicit --license-file (a non-empty
  regular file, no symlink, no parent search, no download) and copies its
  bytes unchanged to LICENSE, listed with size and SHA-256 and covered by
  the archive digest. THIRD_PARTY_NOTICES stays third-party only, and
  bundled Ekklesia code stays in `incorporates`.
- Verifier: rejects missing or invalid license metadata, and a missing,
  unlisted, duplicated, or corrupted LICENSE, through the schema and the
  existing strict inventory.
- Template: packaged as AGPL-3.0-or-later with the repository's canonical
  LICENSE, passed explicitly (Dockerfile, smoke, docs). Packing it twice
  gives byte-identical archives.

Started by Codex; reviewed and completed in Claude Code (empty license-text
refusal, schema non-empty LICENSE, symlink and empty-file tests).

ADR 0051 is Accepted.

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

packages/contracts/package.json

@@ -10,6 +10,10 @@
     ".": {
       "types": "./dist/index.d.ts",
       "import": "./dist/index.js"
+    },
+    "./module-package": {
+      "types": "./dist/module-package.d.ts",
+      "import": "./dist/module-package.js"
     }
   },
   "scripts": {
@@ -22,12 +26,14 @@
   "dependencies": {
     "drizzle-orm": "0.45.2",
     "semver": "7.8.5",
+    "spdx-expression-parse": "5.0.0",
     "zod": "4.4.3"
   },
   "devDependencies": {
     "@biomejs/biome": "2.5.3",
     "@types/node": "24.13.3",
     "@types/semver": "7.7.1",
+    "@types/spdx-expression-parse": "4.0.0",
     "typescript": "7.0.2",
     "vitest": "4.1.10"
   },