First half of Task-multi-email-identity. Lays down everything except the
NextAuth callback wiring, which is gated on a research subagent finishing
its survey of OAuth provider behavior for the email_verified claim
across GitHub, Google, and Authentik.
Schema (packages/database):
* New user_email_identities table colocated with `users` in users.ts.
Columns: id, user_id (FK), email (lowercased), verified_at, source,
created_at, last_used_at.
* Indexes: user_id, email, unique(user_id, email), and a PARTIAL unique
index on email WHERE verified_at IS NOT NULL — a verified email
resolves to exactly one users row globally, while unverified rows
(none today; placeholder for the manual-verification follow-up) do
not share the constraint.
* Drizzle relation: users.emailIdentities -> userEmailIdentities, and
the inverse one(users) relation.
* Migration 0005 generated by db:generate, augmented with a backfill
INSERT that seeds one source='primary' identity per existing users
row using created_at as verified_at. Migration applied to dev DB;
existing admin@tasks.dev user verified as 1:1 mapped.
Server (apps/web/server):
* apps/web/server/lib/identity.ts exports two pure read helpers:
- userOwnsEmail(userId, email): boolean used by the (upcoming)
invite-accept procedure to verify the human controls the invited
address under any of their linked identities.
- findUserIdByVerifiedEmail(email): the replacement for the old
ensureUserIdByEmail lookup. Will be called from auth.ts once the
OAuth research subagent returns.
* apps/web/server/routers/identity.ts exposes identity.listMine — a
protected procedure returning the caller's identities ordered by
verifiedAt desc. Cross-user identity surface is intentionally NOT
exposed here; that lives behind the workspace-scoped autocomplete
in Task 3 with its own tenancy fence.
UI (apps/web/app):
* New route /[workspaceSlug]/settings/profile renders a read-only
"Linked emails" section with per-identity row (email, source badge,
verified state, last-used relative time) plus a hint that explains
how to add another email (sign in via that email's OAuth provider).
* Empty / loading / error states all handled. The "no identities"
branch should never fire post-backfill but renders a friendly
message instead of throwing.
What's NOT in this commit:
* auth.ts changes (ensureUserIdByEmail -> ensureUserIdByVerifiedEmail,
OAuth callback identity upsert, cross-user conflict rejection).
Waiting on subagent research to land the callback wiring correctly
on the first try across all three providers.
* Vitest tests. The pure helpers are 10-line query shims and the
behavior-relevant assertion is the auth callback path — easier to
write meaningful tests once that lands.
All three CI gates green: pnpm lint (14 pre-existing warnings,
unchanged), pnpm type-check (6/6 packages), pnpm test (14/14
existing tests across @tasks/shared, @tasks/database, @tasks/ai).
Co-authored-by: Cursor <cursoragent@cursor.com>