feat: verify email addresses and recover forgotten passwords

Ekklesia could authenticate a person and, since Pass 1, send a
transactional email — but it had no way to establish that an address
belonged to whoever claimed it, and no way back in for someone who
forgot their password.

A verified address is now a precondition for holding a session. Better
Auth enforces that after the password check and before any session
exists, so an unverified sign-in returns 403 with no cookie. That is why
no "unverified principal" was needed: a correct password on an
unverified address carries exactly the authority of no password, and
/api/v1/principal is unchanged.

Better Auth keeps every token. Ekklesia adds no token table, no hashing,
and no expiry clock. It supplies a recipient, a subject, and two bodies,
and the mail provider supplies everything about SMTP.

Verification and reset links are rebuilt from a validated Dashboard
origin, taking only the token — never the URL Better Auth prebuilds from
a caller-supplied callbackURL — so no request can steer where a
recipient lands. Following a verification link mints no session, because
mail infrastructure dereferences links. Reset revokes that person's
other sessions and leaves managed devices alone.

Recovery answers identically for an address with an account, without
one, already verified, or undeliverable — including when SMTP is broken,
which is why the delivery adapter never throws.

The initial platform owner is the one exception: created already
verified by an operator command with no mail prerequisite, so a fresh
server can be signed in to before a relay exists. Migration 0007 extends
that to owners of installations that already exist. Public signup stays
disabled; verification is not a licence to self-register.

Co-Authored-By: Claude Opus 5 <[email protected]>

core/drizzle/0007_verified_bootstrap_owners.sql

@@ -0,0 +1,20 @@
+-- Email verification becomes a precondition for holding a session (ADR 0038). Any platform owner
+-- that already exists was created by the trusted operator-run bootstrap command before that command
+-- marked addresses verified, so without this they would be locked out of their own installation by
+-- an upgrade.
+--
+-- Deliberately narrow. It marks exactly the identities the authorization tables already record as
+-- currently-granted platform owners: an authority the deployment established through a command that
+-- required database credentials, which is the same authority the bootstrap verification exception
+-- rests on. Every other account is left untouched and must verify by email like any other.
+--
+-- Data-only and idempotent. It adds no column, drops nothing, and re-running it changes no row that
+-- is not already false.
+UPDATE "ekklesia_core_user"
+SET "email_verified" = true
+WHERE "email_verified" = false
+  AND "id" IN (
+    SELECT "user_id"
+    FROM "ekklesia_core_platform_owner"
+    WHERE "revoked_at" IS NULL
+  );