feat(auth-ui): login app hardening + Issue #755 fixes + auth-flow findings

Squash of the rebuild branch's enterprise hardening (W1-W10: security, structure,
UX), the datum-cloud/enhancements#755 staging-feedback fixes, and the
auth-flow-sessions campaign findings (F1-F4). Verified on the real local Zitadel
harness and diffed against the old apps/login.

- Sign-in/session: account-switch destination preserved (M10); userAgent payload
  byte-matched to old so cloud-portal shows Device/OS again (M1/S1095); clickable
  account rows (M9); not-found returns 200 inline, no console 404 (F1).
- SSO/IdP: fresh-IdP link falls back to the session user (J2); distinct already-linked
  vs expired-link errors (J1); linked-IdP badge + dedupe (M6); IdP buttons rendered
  only for configured providers (F2).
- Device/CLI: legacy /ui/v2/login/device query passthrough + post-login auto-complete
  so datumctl finishes without a second click (M8); consent layout (M7).
- MFA: skippable nudge suppressed on account-switch while preserving forced MFA (M10);
  decorative authenticator icon (F4); deduped loginName query param (F3).
- Design: dark-mode toggle (M4); SVG signup assets (M3); colors use datum-ui original
  tokens with the cypress-axe color-contrast rule deferred to datum-ui.

Out of scope (infra): M2 logout post_logout_redirect_uri (Pulumi + Envoy).

Author: yahyafakhroji

.dependency-cruiser.cjs

@@ -0,0 +1,60 @@
+// .dependency-cruiser.cjs
+module.exports = {
+  forbidden: [
+    {
+      // The composition seam: only server/composition.ts may reach across into a provider
+      // adapter. A provider package composing its OWN cohesive sibling modules
+      // (the zitadel monolith was decomposed into capability modules under
+      // providers/zitadel/ — index.ts delegates to user/settings/session/… which share
+      // mappers/transport) is intra-package composition, not a cross-boundary import, so it
+      // is exempted via the `from` pathNot. The guard still flags every import that reaches
+      // into providers/ from OUTSIDE the providers tree (e.g. select.server.ts).
+      // Exemptions:
+      //  - Test files (`__tests__/` and `*.{test,spec}.{ts,tsx}`) legitimately import the
+      //    fake provider directly to drive service/route units against a deterministic
+      //    in-process double. This is test wiring, not production cross-boundary coupling.
+      //  - `app/modules/auth/select.server.ts` is the provider registry seam: the
+      //    single concrete-provider selection site (zitadel|fake), a legitimate second
+      //    composition seam alongside server/composition.ts. It is the one place outside the
+      //    providers tree allowed to name a concrete provider.
+      name: 'only-composition-imports-providers',
+      severity: 'error',
+      from: {
+        pathNot:
+          'app/server/composition\\.ts$|^app/modules/auth/providers/|__tests__/|\\.(test|spec)\\.(ts|tsx)$|^app/modules/auth/select\\.server\\.ts$',
+      },
+      to: { path: 'app/modules/auth/providers/' },
+    },
+    {
+      name: 'resources-not-server-edge',
+      severity: 'error',
+      from: { path: 'app/resources/' },
+      to: { path: 'app/server/edge/' },
+    },
+    {
+      name: 'shared-is-leaf',
+      severity: 'error',
+      from: { path: 'app/shared/' },
+      to: { path: 'app/(routes|resources|modules|server|components)/' },
+    },
+    {
+      // `app/routes/paths.ts` is a pure typed-path constant module (URL string builders,
+      // no route/loader/action behavior). Resources importing it for redirect targets is a
+      // constant dependency, not a layering violation, so it is exempted from this guard.
+      name: 'no-routes-from-resources',
+      severity: 'error',
+      from: { path: 'app/resources/' },
+      to: { path: 'app/routes/', pathNot: 'app/routes/paths\\.ts$' },
+    },
+    {
+      name: 'no-circular',
+      severity: 'error',
+      from: {},
+      to: { circular: true },
+    },
+  ],
+  options: {
+    tsConfig: { fileName: 'tsconfig.json' },
+    doNotFollow: { path: 'node_modules' },
+  },
+};

.github/CODEOWNERS

@@ -0,0 +1,3 @@
+# Code review ownership for datum-cloud/auth-ui.
+# Default owner for everything in the repo.
+*   @datum-cloud/portals

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,48 @@
+---
+name: Bug report
+about: Report a defect in auth-ui (a reproducible, non-security problem)
+title: ""
+labels: bug
+assignees: ""
+---
+
+## Summary
+
+A clear, one- or two-sentence description of the bug.
+
+## Steps to reproduce
+
+1. Go to '...'
+2. Sign in with provider '...'
+3. Click '...'
+4. See the error
+
+## Expected vs actual
+
+**Expected:** what you expected to happen.
+
+**Actual:** what actually happened.
+
+## Environment
+
+- auth-ui image / commit sha: <!-- e.g. ghcr.io/datum-cloud/auth-ui:<sha>, or the sha shown in the footer -->
+- Browser & version: <!-- e.g. Chrome 126, Safari 17.5, Firefox 127 -->
+- Auth provider: <!-- `fake` (local dev) or `zitadel` -->
+- Deployment: <!-- local dev / staging / production -->
+
+## Logs
+
+Paste any relevant console output, network responses, or server logs.
+
+> **Redact secrets and personal data** before pasting — strip tokens, cookies,
+> `Authorization` headers, email addresses, and login names.
+
+```text
+(paste redacted logs here)
+```
+
+## Security note
+
+> If this is a **security vulnerability**, do **not** file it here. Report it
+> privately via [SECURITY.md](../../SECURITY.md) →
+> [Report a vulnerability](https://github.com/datum-cloud/auth-ui/security/advisories/new).

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Report a security vulnerability
+    url: https://github.com/datum-cloud/auth-ui/security/advisories/new
+    about: Please report security issues privately, not as public issues.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,38 @@
+---
+name: Feature request
+about: Propose a new capability or improvement for auth-ui
+title: ""
+labels: enhancement
+assignees: ""
+---
+
+## Problem / Motivation
+
+What problem does this solve, and for whom? Describe the user or operator pain
+point — not the solution. Link to any related issues or discussions.
+
+## Proposed solution
+
+The change you'd like to see. Be concrete: which routes, flows, or components
+would change, and what the resulting behavior should be.
+
+## Alternatives considered
+
+Other approaches you weighed, and why they were set aside (including doing
+nothing).
+
+## Scope / impact
+
+Check anything this proposal would touch — these areas carry extra review:
+
+- [ ] **URLs / redirects** — adds or changes a route, redirect, or callback URL
+      (URLs are byte-frozen; changes require the URL-resolution gate)
+- [ ] **Auth flows** — sign-in, MFA, IdP linking, session, or logout behavior
+- [ ] **Boundary layers** — `routes` → `resources` → `modules` → `providers`,
+      or the `server/` layer (subject to the architecture-fitness gate)
+- [ ] **Env / configuration** — adds or changes a validated env variable
+- [ ] None of the above (self-contained UI or internal change)
+
+## Additional context
+
+Mockups, references, or links that help evaluate the request.

.github/pull_request_template.md

@@ -0,0 +1,39 @@
+<!--
+Thanks for contributing to datum-cloud/auth-ui.
+Fill in each section. Keep the PR focused — one logical change per PR.
+-->
+
+## Summary
+
+What does this PR change, and why? Describe the behavior before and after.
+
+## Linked issue
+
+<!-- e.g. Closes #123 / Refs #456 -->
+
+## Type
+
+- [ ] feat — new user-facing capability
+- [ ] fix — bug fix
+- [ ] refactor — behavior-preserving restructure
+- [ ] chore — tooling, deps, or housekeeping
+- [ ] docs — documentation only
+- [ ] test — tests only
+- [ ] perf — performance improvement
+
+## Checklist
+
+- [ ] `bun run typecheck` passes
+- [ ] `bun run lint:ci` passes (no new `console.*` — guarded by the `no-console` rule)
+- [ ] `bun run test:unit` passes
+- [ ] **URLs are byte-frozen** — no route, redirect, or callback URL changed
+      without going through the URL-resolution gate
+- [ ] **No raw PII in logs** — login names / emails are hashed (`hashActor`) or
+      redacted; no secrets, tokens, or cookies logged
+- [ ] `CHANGELOG.md` `[Unreleased]` updated (if this change is user-facing)
+- [ ] Boundary layers respected (`routes` → `resources` → `modules` →
+      `providers`); `bun run lint:boundaries` passes if layers were touched
+
+## Screenshots
+
+<!-- For UI changes, include before/after screenshots. Delete this section otherwise. -->

.gitignore

@@ -23,3 +23,6 @@ e2e-artifacts/
 # Internal working docs (planning/specs/issues — not part of the shipped repo)
 docs/issues/
 docs/superpowers/
+# Playwright run artifacts
+test-results/
+playwright-report/

CHANGELOG.md

@@ -0,0 +1,58 @@
+# Changelog
+
+All notable changes to this project are documented here.
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [0.1.0] — 2026-06-23
+
+First public-release candidate. Covers the enterprise audit-remediation run
+(waves W1–W10): the safety-net + governance foundation (W1–W3), the
+component/route refactor and god-route split (W4–W7), type & PnP hardening (W8),
+error-handling completion (W9), and the perf/UX/a11y finalize gate (W10). All
+ten wave gates closed green; auth URLs are byte-frozen across the run.
+
+### Added
+- MIT `LICENSE`, `SECURITY.md`, `CONTRIBUTING.md`, `CODE_OF_CONDUCT.md`
+  (Contributor Covenant v2.1), `CODEOWNERS`, and GitHub issue/PR templates
+  (enterprise OSS governance).
+- Architecture-fitness gate (`dependency-cruiser`/`madge`), v8 coverage with a ratchet
+  floor, byte-frozen URL-resolution e2e suite, and a visual-regression baseline.
+- `no-console` lint guard; client-bundle size budget (first-load gzip).
+- `<BackLink/>` predecessor navigation across the setup and password ceremony
+  routes (authenticator, passkey, security-key, email, sms, mfa, password new/change).
+- TOTP enrollment QR code (`qrcode.react`) on the authenticator setup screen,
+  with the manual secret key retained as a fallback.
+- Branding on the login-method screen, consistent with the other branded ceremony
+  screens.
+- Pluggable rate-limit store interface with an env-gated `ioredis` sliding-window
+  adapter (`RATE_LIMIT_REDIS_URL`); the in-memory store remains the default.
+- Accessibility regression guards: `axe-core` structural/aria unit tests,
+  keyboard focus-order tests, and a `prefers-reduced-motion` test across the
+  ceremony components, plus a one-time live `cypress-axe` contrast audit.
+- `webauthn-enroll` factory consolidating passkey and security-key enrollment.
+
+### Changed
+- CSP `style-src` hardened to a per-request nonce (dropped `'unsafe-inline'`).
+- `ALLOW_IDP_UNLINK` now resolved through the validated env schema.
+- Error surface consolidated to the single inline `<AuthCeremony error>` banner;
+  inline recovery affordances added for expired-session and unsupported-method states.
+- Architecture-fitness gate flipped from `warn` to `error` severity (legitimate
+  composition/registry/path-constant seams exempted with justification).
+- `getLoginSettings`, `/accounts` auth-method lookups, the SSO callback/link RPCs,
+  and session create/update were deduped/batched/memoized — fewer calls, identical
+  observable output.
+
+### Fixed
+- Rate-limit audit logs redact `loginName` via `hashActor` (no raw PII).
+- `last-used-login` cookie scoped to `/id`.
+- Contextless device-authorization requests (missing `user_code`) now redirect to
+  `/device` instead of rendering an error page; stale/expired codes keep the
+  tailored recovery screen.
+- `sso/link` validates `returnTo` against a same-origin allowlist and uses a
+  `Link` to login in place of a GET form.
+
+### Removed
+- Unused `@tanstack/react-query` and `@tanstack/react-virtual` dependencies.

CODE_OF_CONDUCT.md

@@ -0,0 +1,85 @@
+
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our community a harassment-free experience for everyone, regardless of age, body size, visible or invisible disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, caste, color, religion, or sexual identity and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming, diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes, and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of acceptable behavior and will take appropriate and fair corrective action in response to any behavior that they deem inappropriate, threatening, offensive, or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, and will communicate reasons for moderation decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when an individual is officially representing the community in public spaces. Examples of representing our community include using an official e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported to the community leaders responsible for enforcement via GitHub private vulnerability reporting (repository Security tab) or by contacting @datum-cloud/portals. All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing clarity around the nature of the violation and an explanation of why the behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, for a specified period of time. This includes avoiding interactions in community spaces as well as external channels like social media. Violating these terms may lead to a temporary or permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public communication with the community for a specified period of time. No public or private interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, is allowed during this period. Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community standards, including sustained inappropriate behavior, harassment of an individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 2.1, available at [https://www.contributor-covenant.org/version/2/1/code_of_conduct.html][v2.1].
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct enforcement ladder][Mozilla CoC].
+
+For answers to common questions about this code of conduct, see the FAQ at [https://www.contributor-covenant.org/faq][FAQ]. Translations are available at [https://www.contributor-covenant.org/translations][translations].
+
+[homepage]: https://www.contributor-covenant.org
+[v2.1]: https://www.contributor-covenant.org/version/2/1/code_of_conduct.html
+[Mozilla CoC]: https://github.com/mozilla/diversity
+[FAQ]: https://www.contributor-covenant.org/faq
+[translations]: https://www.contributor-covenant.org/translations
+