AlgoSu ADR

Background

New user onboarding required a multi-step registration flow. The existing auth flow jumped directly from OAuth callback to the main dashboard with no profile setup step. Sprint 101 introduces a 3-page registration wizard and performs MEMORY.md housekeeping.

Goals

Create /register page (registration entry, OAuth provider selection)
Create /register/profile page (display name, avatar, study preferences)
Create /register/github page (GitHub account linking for submission tracking)
Clean up MEMORY.md entries older than 30 sprints

Work Summary

Commit	Agent	Content
`a1b2c3d`	architect	RegisterLayout + 3 page skeletons
`e4f5g6h`	herald	i18n keys for registration flow (KR + EN)
`i7j8k9l`	architect	Profile form — display name + avatar upload
`m0n1o2p`	architect	GitHub linking — OAuth2 PKCE flow
`q3r4s5t`	scribe	MEMORY.md cleanup — removed Sprint 60–70 inline detail

Changes

Page Structure

app/[locale]/register/
  layout.tsx          — RegisterLayout (stepper + progress indicator)
  page.tsx            — Step 1: Registration entry
  profile/
    page.tsx          — Step 2: Profile setup
  github/
    page.tsx          — Step 3: GitHub linking

Registration Flow

/register — Entry page. Displays "Complete your profile to get started" CTA. Shows current OAuth provider (Google/GitHub). "Continue" button advances to /register/profile.
/register/profile — Display name input (2–30 chars, profanity filter), avatar upload (≤2MB JPEG/PNG, cropped to 200×200), study timezone selection. "Save & Continue" → /register/github.
/register/github — GitHub OAuth2 PKCE flow to link a separate GitHub account for submission file tracking. "Skip for now" allowed — GitHub linking is optional.

Stepper Component

TSX

<RegisterStepper
  steps={[
    { label: t('stepRegister'), href: '/register' },
    { label: t('stepProfile'), href: '/register/profile' },
    { label: t('stepGithub'), href: '/register/github' },
  ]}
  currentStep={currentStep}
/>

MEMORY.md Cleanup

Removed inline detail for sprints 60–70 (moved to topic files in .claude/projects/memory/)
Reduced MEMORY.md from 28KB to 18KB
Preserved sprint index entries (1-line summaries retained)

Verification

Item	Result
`/register` renders correctly	✅
`/register/profile` — form validation	✅
`/register/github` — PKCE flow	✅
Stepper progress indicator	✅
i18n KR + EN	✅
`tsc --noEmit`	✅ 0 errors

Decisions

3-page wizard over single form: Each step has distinct UX requirements and can fail independently. Multi-page is more resilient (partial completion survives refresh).
GitHub linking optional: Forcing GitHub linking at registration would block users who use other hosting. Optional step with "skip" maintains accessibility.
PKCE for GitHub OAuth2: PKCE (Proof Key for Code Exchange) is required for public clients (browser-side). No client secret stored in frontend.
MEMORY.md cleanup: Files over 24KB trigger warnings. Pruning inline detail to topic files is the standard maintenance pattern.

Register 3 Pages + MEMORY.md Cleanup

Key Decisions

3-page wizard over single form

GitHub linking optional

PKCE for GitHub OAuth2

MEMORY.md cleanup