feat(orders): record what we thought of an order, per person

The ledger already knew we had ordered from a place; it did not know the
food was bad. Orders got repeated from places we disliked because nobody
remembered by the time the next one went in. That is what the receipt
ingestion was for (ING-9) and the last piece was missing: order_reviews
existed as a table with no API, no UI and no writes.

Four levels, not three. "Loved" and "liked" are both "would order again"
but only one is worth a detour, and "ok" is not a recommendation.

A verdict belongs to a person, not to an order. A shared meal produces
two opinions and they routinely disagree — that disagreement is the
useful part, and the old UNIQUE on transaction_id alone could not hold
it. Now UNIQUE (transaction_id, participant_id), and the default is the
signed-in user rather than the owner: Sonu authenticates through the same
Traefik OAuth as participant 4, so an owner default would have filed her
verdict under his name.

Per-item opinions key on the item DESCRIPTION, not its index. An index is
meaningless across orders; "the Pad Thai here is good" is the signal that
has to survive into the next order from the same merchant. Only the two
poles are offered — a per-item "ok" answers neither of the questions you
ask at order time.

Sharing is recorded as a real 50/50 split, not a decorative flag. The
split already IS the record that an order was shared, and two records of
one fact drift apart.

An ABSENT item_verdicts means "leave them alone"; an empty array clears
them. Without that distinction a note-only save silently wipes every
per-item opinion — the same shape as the bug that reset `settled` on
split rewrites, and just as invisible on screen. Mutation-tested: making
keepItems a no-op fails exactly one test.

mockDbWithPool gained queryRow. Omitting an export from the mock makes it
undefined at the call site, which fails as "not a function" and reads
like a code bug rather than a test-harness gap.

prisma/schema.prisma

@@ -42,6 +42,7 @@ model participants {
   account_owner_mappings account_owner_mappings[]
   payments_sent         split_payments[]         @relation("payments_from")
   payments_received     split_payments[]         @relation("payments_to")
+  order_reviews         order_reviews[]
 }
 
 model account_owner_mappings {
@@ -192,7 +193,7 @@ model transactions {
   superseded_by           transactions?  @relation("superseded", fields: [superseded_by_id], references: [id], onDelete: SetNull)
   supersedes              transactions[] @relation("superseded")
   expense_metadata        expense_metadata?
-  order_review            order_reviews?
+  order_reviews           order_reviews[]
 }
 
 model expense_metadata {
@@ -221,7 +222,8 @@ model expense_metadata {
 
 model order_reviews {
   id             Int          @id @default(autoincrement())
-  transaction_id Int          @unique
+  transaction_id Int
+  participant_id Int
   rating         String?
   order_again    Boolean?
   note           String?
@@ -229,6 +231,9 @@ model order_reviews {
   created_at     DateTime     @default(now())
   updated_at     DateTime     @updatedAt
   transaction    transactions @relation(fields: [transaction_id], references: [id], onDelete: Cascade)
+  participant    participants @relation(fields: [participant_id], references: [id], onDelete: Cascade)
+
+  @@unique([transaction_id, participant_id], name: "order_reviews_transaction_participant_key")
 }
 
 model rule_apply_runs {