feat: one generic image, with installed modules in installation-owned storage (ADR 0048)

The production image now contains zero feature modules and is the same for every
installation. Installed modules live in module storage that one Core resolver
selects from EKKLESIA_MODULES_DIR: the checkout's modules/ when unset, an
absolute path that must exist when set (/var/lib/ekklesia/modules in the image).
A relative, blank, missing, or unreadable configured directory fails closed with
a sanitized error that never contains the value.

- Host configuration reads EKKLESIA_MODULES_DIR. The API, migration plan, apply
  and validate, module validation, module enablement, and Doctor all resolve it
  the same way; the test-only API override still takes precedence.
- Doctor receives Core's migrations directory explicitly instead of deriving it
  from the modules directory's parent.
- The migration runner retains and reports the applied history of a module that
  is not installed, and plans and applies Core's and present modules' migrations
  around it. Core's history and every installed module's history stay strict: a
  missing or changed applied migration, or a downgrade, still fails. No down
  migrations, no data deletion.
- deploy/Dockerfile copies no module and installs nothing for the module
  template; .dockerignore excludes modules/ and the build refuses a context that
  contains it; the runtime has an empty root-owned /var/lib/ekklesia/modules and
  sets EKKLESIA_MODULES_DIR.
- deploy/compose.yaml bind-mounts EKKLESIA_MODULES_HOST_DIR read-only into api
  and migrate, with create_host_path disabled.
- scripts/check-image.sh proves the image holds no modules and that a populated
  modules/ directory leaves its runtime file system identical; CI runs it.
- The split deploy smoke now uses the same generic image: it boots with no
  modules, installs a self-contained test module packaged from the template
  (test-only), migrates and restarts, removes it (Core runs, planning reports the
  retained history, data survives), and restores it with its data.

Docs: deploy README (module storage, install/update/remove/restore, the runtime
modules target), .env.example, API configuration, module development guide,
testing, workflow, security, and the architecture overview.

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

core/tests/modules-directory-commands.test.ts

@@ -0,0 +1,116 @@
+import { cp, mkdtemp, readdir, readFile, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { afterEach, describe, expect, it } from "vitest";
+import { discoverRepositoryMigrations } from "../src/cli/migration-command-support.js";
+import { resolveCommandModulesDirectory } from "../src/cli/modules-directory-environment.js";
+import { ModuleDiscoveryError } from "../src/modules/index.js";
+
+const repositoryRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..", "..");
+const templateModule = path.join(repositoryRoot, "templates", "module");
+const temporaryDirectories: string[] = [];
+
+afterEach(async () => {
+  await Promise.all(
+    temporaryDirectories.splice(0).map((directory) => rm(directory, { recursive: true })),
+  );
+});
+
+async function externalModulesDirectory(): Promise<string> {
+  const directory = await mkdtemp(path.join(tmpdir(), "ekklesia-installed-modules-"));
+  temporaryDirectories.push(directory);
+  return directory;
+}
+
+/** Installs the module template's migration-bearing package files as module `example`. Migration
+ * discovery imports nothing, so the template's manifest, package metadata, and migrations are all
+ * it reads; the compiled artifacts discovery checks for are copied too when they exist. */
+async function installTemplate(modulesDirectory: string): Promise<void> {
+  const target = path.join(modulesDirectory, "example");
+  for (const entry of ["package.json", "ekklesia.module.json", "drizzle", "dist"]) {
+    await cp(path.join(templateModule, entry), path.join(target, entry), { recursive: true });
+  }
+}
+
+describe("operator commands select the modules directory through host configuration", () => {
+  it("defaults to the repository's own modules directory", () => {
+    expect(resolveCommandModulesDirectory({}, "/opt/ekklesia")).toEqual({
+      modulesDirectory: "/opt/ekklesia/modules",
+      modulesDirectoryRequired: false,
+    });
+  });
+
+  it("honours EKKLESIA_MODULES_DIR", () => {
+    expect(
+      resolveCommandModulesDirectory(
+        { EKKLESIA_MODULES_DIR: "/var/lib/ekklesia/modules" },
+        "/opt/ekklesia",
+      ),
+    ).toEqual({ modulesDirectory: "/var/lib/ekklesia/modules", modulesDirectoryRequired: true });
+  });
+
+  it("refuses a relative EKKLESIA_MODULES_DIR without echoing it", () => {
+    expect(() =>
+      resolveCommandModulesDirectory({ EKKLESIA_MODULES_DIR: "modules-9e1f" }, "/opt/ekklesia"),
+    ).toThrow(ModuleDiscoveryError);
+    try {
+      resolveCommandModulesDirectory({ EKKLESIA_MODULES_DIR: "modules-9e1f" }, "/opt/ekklesia");
+    } catch (error) {
+      expect(JSON.stringify((error as ModuleDiscoveryError).issues)).not.toContain("9e1f");
+    }
+  });
+
+  it("plans migrations for modules installed outside the repository, with Core's from the platform", async () => {
+    const modulesDirectory = await externalModulesDirectory();
+    await installTemplate(modulesDirectory);
+
+    const aggregate = await discoverRepositoryMigrations(repositoryRoot, {
+      EKKLESIA_MODULES_DIR: modulesDirectory,
+    });
+
+    const sources = aggregate.modules.map((module) => module.moduleId);
+    expect(sources[0]).toBe("core");
+    expect(sources).toContain("example");
+    expect(
+      aggregate.migrations.some((migration) => migration.identity === "example:0000_initial"),
+    ).toBe(true);
+    const coreTags = (await readdir(path.join(repositoryRoot, "core", "drizzle"))).filter((name) =>
+      name.endsWith(".sql"),
+    );
+    expect(aggregate.modules[0]?.migrations).toHaveLength(coreTags.length);
+  });
+
+  it("fails closed when the configured directory does not exist", async () => {
+    const parent = await externalModulesDirectory();
+    await expect(
+      discoverRepositoryMigrations(repositoryRoot, {
+        EKKLESIA_MODULES_DIR: path.join(parent, "absent"),
+      }),
+    ).rejects.toBeInstanceOf(ModuleDiscoveryError);
+  });
+});
+
+describe("no source chooses a modules directory except the resolver", () => {
+  async function sourceFiles(directory: string): Promise<readonly string[]> {
+    const entries = await readdir(directory, { recursive: true, withFileTypes: true });
+    return entries
+      .filter((entry) => entry.isFile() && entry.name.endsWith(".ts"))
+      .map((entry) => path.join(entry.parentPath, entry.name));
+  }
+
+  it("never joins `modules` onto a root anywhere else in Core or the API", async () => {
+    const files = [
+      ...(await sourceFiles(path.join(repositoryRoot, "core", "src"))),
+      ...(await sourceFiles(path.join(repositoryRoot, "apps", "api", "src"))),
+    ];
+    const resolver = path.join(repositoryRoot, "core", "src", "modules", "modules-directory.ts");
+    for (const file of files) {
+      if (file === resolver) {
+        continue;
+      }
+      const text = await readFile(file, "utf8");
+      expect(text, path.relative(repositoryRoot, file)).not.toMatch(/,\s*"modules"\s*\)/u);
+    }
+  });
+});