feat(inbox): match non-invoice documents via prominent amounts (#2048)

* feat(inbox): match non-invoice documents via prominent amounts

Bankintyg, bank agreements and other documentKind "other" PDFs carry no
invoice-style total, so extraction correctly left totals.total null and the
document became structurally unmatchable: findUnderlagCandidates hard-drops
items without a comparable amount and the picker lost the 40% amount signal.

- extraction: new prominentAmounts[] field (amount + document's own label),
  populated only when totals.total is null; account/org/phone/reference
  numbers and zero amounts excluded. totals.total semantics untouched.
- matching: bestProminentAmountVariance() tries each printed amount and
  feeds calculateMatchConfidence at reduced weight (0.3 vs 0.4) in both the
  agent candidate scorer and TransactionMatchPicker.
- UI: inbox rail shows the detected amounts read-only for such documents,
  list falls back to a single distinct prominent amount, and extraction no
  longer reads as "found nothing".

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm9QgdyNAFaWiz6Ww7pgb

* fix(inbox): discount prominent-amount fallback instead of reweighting it

Skeptic pass refutations on the first commit: normalized weighting made a
reduced amount weight self-defeating. Date + exact fallback amount with no
merchant scored (0.25+0.3)/0.55 = 1.0 ("100% sakerhet" on a wrong same-day
transaction), and a DISAGREEING fallback amount scored above a disagreeing
invoice total (0.67 vs 0.60) because shrinking the weight also shrank the
penalty.

- score fallbacks at full amount weight, then multiply by a flat
  FALLBACK_CONFIDENCE_FACTOR (0.85): agreement caps below certainty,
  disagreement stays at least as damning as for a real total.
- agent candidate surface additionally requires the document date within
  DATE_TOLERANCE_DAYS, so an avtal listing 349 kr no longer matches every
  future 349 kr charge from the same counterparty.
- bestProminentAmountVariance returns which amount matched + its document
  label, and the match reason names it ("Exakt belopp i dokumentet: 2 500
  SEK (Engangspris)"): no more bare "Exakt belopp" reaching the agent while
  total_amount is null.
- prompt: prominentAmounts restricted to non-invoice documentKinds, and
  never a parking spot for an unreadable invoice total.
- fix the stale "deliberately the same list" comment on
  EXTRACTED_FIELD_ACCESSORS.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm9QgdyNAFaWiz6Ww7pgb

* fix(receipt-hunt): never propose on the prominent-amounts fallback

Second skeptic pass: the nightly hunt is a third consumer of
scoreUnderlagCandidates and inherited the fallback unaware. A bankintyg
whose printed "Insatt belopp" equals a same-day outflow scores 0.85, which
clears CERTAIN_CONFIDENCE (0.8) and skips LLM adjudication, on a pairing
wrong by construction (the hunt scans outflows only; "Insatt belopp"
labels an inflow), with document_amount null in the approval preview.

UnderlagCandidate now carries amountSource ('total' | 'prominent') and
selectProposals drops fallback-scored candidates. Non-invoice documents
stay reachable through the manual picker and the agent candidate surface,
both of which have a human reading the amounts.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm9QgdyNAFaWiz6Ww7pgb

* fix(inbox): round fallback confidence via roundOre, not the naive pattern

The two confidence discounts (and their test) tripped the naive-ore-round
antipattern ratchet (625 vs baseline 622); use the sanctioned helper.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm9QgdyNAFaWiz6Ww7pgb

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

types/index.ts

@@ -4390,6 +4390,10 @@ export interface InvoiceExtractionResult {
     roundingAmount?: number | null
   }
   vatBreakdown: VatBreakdownItem[]
+  // Amounts visible on non-invoice documents (bankintyg, avtal, contracts)
+  // with no invoice-style total. Matching hint only, never booked. Optional:
+  // extractions from before the field existed lack it.
+  prominentAmounts?: ProminentAmount[]
   confidence: number
   suggestedTemplateId?: string
   // Set by the caller (not the model) when a long PDF was sliced before
@@ -4414,6 +4418,12 @@ export interface VatBreakdownItem {
   amount: number
 }
 
+/** One amount printed on a non-invoice document, with the document's own label. */
+export interface ProminentAmount {
+  amount: number
+  label: string | null
+}
+
 // KPI Report
 export interface KPIReport {
   netResult: number                // SEK