Phase 0 scaffold: arcadia-cloud Phoenix service

API-only Phoenix 1.8 project for cloud-ops, inventory, billing, and
provisioning sagas. Validates arcadia JWTs via shared Guardian secret
(verify-only; arcadia-app remains the issuer).

Deps beyond default Phoenix: guardian, cors_plug, oban, req.
Postgres on local port 5433 per arcadia stack convention.
Endpoint runs on :4005.

Endpoints:
- GET /api/health         — public, returns service identifier
- GET /api/v1/inventory   — auth-gated, returns empty list (phase 0 stub)

Oban configured with the queues phase 1+ will need:
provisioning / cloud_sync_fast|full|slow / cloud_billing / metering.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

config/test.exs

@@ -0,0 +1,31 @@
+import Config
+
+# Configure your database
+#
+# The MIX_TEST_PARTITION environment variable can be used
+# to provide built-in test partitioning in CI environment.
+# Run `mix help test` for more information.
+config :arcadia_cloud, ArcadiaCloud.Repo,
+  username: "postgres",
+  password: "postgres",
+  hostname: "localhost",
+  database: "arcadia_cloud_test#{System.get_env("MIX_TEST_PARTITION")}",
+  pool: Ecto.Adapters.SQL.Sandbox,
+  pool_size: System.schedulers_online() * 2
+
+# We don't run a server during test. If one is required,
+# you can enable the server option below.
+config :arcadia_cloud, ArcadiaCloudWeb.Endpoint,
+  http: [ip: {127, 0, 0, 1}, port: 4002],
+  secret_key_base: "ZzGlsnmuVC9wkMb6PaYLDsuiL71jzgbDOvIFe3TyxGah3lDHO+dxmrEDJyz6mFe6",
+  server: false
+
+# Print only warnings and errors during test
+config :logger, level: :warning
+
+# Initialize plugs at runtime for faster test compilation
+config :phoenix, :plug_init_mode, :runtime
+
+# Sort query params output of verified routes for robust url comparisons
+config :phoenix,
+  sort_verified_routes_query_params: true