add CI pipeline with credo and dialyzer

mix ci alias: compile --warning-as-errors, format --check-formatted,
credo, dialyzer, test. Credo configured with sensible defaults.
Dialyzer ignore file for false positives (Stripe types, Mix tasks,
ExUnit internals). Credo fixes: map_join, filter consolidation,
nesting extraction, cond→if simplification.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

PROGRESS.md

@@ -20,7 +20,7 @@
 - Transactional emails (order confirmation, shipping notification)
 - Demo content polished and ready for production
 
-**Tier 1 MVP complete.** Next up: Tier 2 — hosting & deployment.
+**Tier 1 MVP complete.** CI pipeline done. Next up: Tier 2 — hosting & deployment.
 
 ## Roadmap
 
@@ -35,7 +35,7 @@
 
 5. **Hosting & deployment** — Fly.io or similar deployment config. Release configuration, runtime env setup, health checks. Observability: structured logging, error tracking (Sentry or similar), basic metrics.
 6. **Litestream / SQLite replication** — Litestream for continuous SQLite backup to S3-compatible storage. Point-in-time recovery. Simple sidecar process, no code changes needed, works with vanilla SQLite. For the hosted platform (Tier 5), evaluate [Turso](https://turso.tech/) (libSQL fork of SQLite) with embedded read replicas via [ecto_libsql](https://github.com/ocean/ecto_libsql) adapter — gives multi-node reads without a separate replication daemon, but adds a dependency on the libSQL fork.
-7. **CI pipeline** — All checks implemented as mix aliases (`mix ci` wrapping `mix precommit` + credo + dialyzer). CI config is a thin wrapper that calls `mix ci` — portable across GitHub Actions, Forgejo Actions, Woodpecker, or plain SSH. No proprietary CI dependencies. Custom mix tasks for anything project-specific (e.g. `mix lighthouse`). Oban stays for runtime background jobs, not CI.
+7. ~~**CI pipeline**~~ — ✅ Complete. `mix ci` alias: compile --warning-as-errors, deps.unlock --unused, format --check-formatted, credo, dialyzer, test. Credo configured with sensible defaults. Dialyzer with ignore file for false positives (Stripe types, Mix tasks, ExUnit internals). 612 tests, 0 failures.
 8. **PageSpeed in CI** — Lighthouse CI to catch regressions. Fail the build if score drops below threshold. Protects the current 100% score.
 9. **End-to-end tests** — Wallaby or similar for browser-based tests of critical flows: browse → add to cart → checkout → order confirmation. Covers the full happy path plus key error cases.
 
@@ -219,6 +219,16 @@ All shop pages now have LiveView integration tests (612 total):
 - **Collection page** (16 tests, pre-existing) — category filtering, sorting, URL params
 - **Content pages** (10 tests, pre-existing) — about, delivery, privacy, terms
 
+### CI Pipeline
+**Status:** Complete
+
+- `mix ci` alias: compile --warning-as-errors → deps.unlock --unused → format --check-formatted → credo → dialyzer → test
+- `mix precommit` alias: compile --warning-as-errors → deps.unlock --unused → format → test
+- Credo with tuned config (disabled AliasUsage, ModuleDoc, PredicateFunctionNames; relaxed line length, nesting, complexity)
+- Dialyzer with ignore file for known false positives (Stripe library types, Mix.Task dev-only modules, ExUnit internals)
+- All credo issues resolved (map_join, filter consolidation, nesting extraction)
+- 612 tests, 0 failures
+
 ### Page Editor
 **Status:** Future (Tier 4)
 
@@ -232,6 +242,7 @@ See: [docs/plans/page-builder.md](docs/plans/page-builder.md) for design
 
 | Feature | Commit | Notes |
 |---------|--------|-------|
+| CI pipeline | — | mix ci/precommit aliases, credo, dialyzer, 612 tests |
 | Default content pages | 5a43cfc | Generic Content LiveView, delivery/privacy/terms pages, 10 tests |
 | Transactional emails | — | Plain text order confirmation + shipping notification, 10 tests |
 | Printify order submission & fulfilment | — | Submit, track, webhooks, polling, admin UI, 33 tests |