fix(journal): single-use JWT enforcement for route callback tokens (#2 Phase B)

After Phase A (#442) moved the journal callback token off the browser,
the token was still replayable on the wire until \`exp\` (7 days). This
PR makes each token strictly single-use.

Changes:

- **\`journal.consumed_jwt_jti\` table** — \`jti TEXT PRIMARY KEY,
  consumed_at TIMESTAMPTZ, expires_at TIMESTAMPTZ\`. Picked up by
  drizzle-kit push on deploy.
- **\`createRouteToken\` now sets a \`jti\` claim** (\`randomUUID()\`).
- **\`verifyRouteToken\` atomically consumes the jti** via
  \`INSERT … ON CONFLICT DO NOTHING RETURNING jti\`. Postgres
  serializes the insert, so exactly one concurrent caller wins; the
  rest see an empty result and throw \`TokenAlreadyConsumedError\`.
  Tokens without a \`jti\` claim (i.e. minted before this PR) are
  also rejected — the right call: any in-flight legacy token sitting
  in a planner session is replayable, and we'd rather fail-loud than
  silently grandfather them in.
- **\`consumed-jti-sweep\` job** — daily 03:45 UTC cron that
  \`DELETE WHERE expires_at < now()\`. Keeps the table tiny; offset
  from the other purge jobs to spread load.
- **e2e replay test** — \`integration.test.ts\` now exercises a
  same-token double-submit and asserts the second returns 401 with
  \`/consumed|already/i\`.

UX implication worth flagging: a user who clicks \"Save\" twice (or whose
network retries a failed POST) sees an error on the second attempt.
They go back to the journal for a fresh \"Edit in Planner\" link.

Full repo: pnpm typecheck / lint / test all green (177 + 31 integration).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/db/src/schema/journal.ts

@@ -356,3 +356,17 @@ export const notifications = journalSchema.table("notifications", {
     .on(t.recipientUserId, t.type, t.subjectId)
     .where(sql`${t.subjectId} IS NOT NULL`),
 }));
+
+// Single-use JWT enforcement for callback tokens (planner → journal
+// save flow). Each token carries a `jti` claim; the verifier inserts
+// into this table on first use. A second attempt hits the PK conflict
+// and the verifier rejects the token. Rows are swept after `expires_at`.
+// See spec / planner-audit #2 Phase B.
+export const consumedJwtJti = journalSchema.table("consumed_jwt_jti", {
+  jti: text("jti").primaryKey(),
+  consumedAt: timestamp("consumed_at", { withTimezone: true }).notNull().defaultNow(),
+  expiresAt: timestamp("expires_at", { withTimezone: true }).notNull(),
+}, (t) => ({
+  // Sweep runs `DELETE WHERE expires_at < now()` on a daily schedule.
+  expiresAtIdx: index("consumed_jwt_jti_expires_at_idx").on(t.expiresAt),
+}));