fix(transactions): the underlag column is one surface, not a dropzone and an orphan button (#1628)

* fix(transactions): the underlag column is one surface, not a dropzone and an orphan button

The Bokfor transaktion dialog stretched its empty dropzone into a
45/72vh well and pinned "Valj befintligt underlag" alone at the very
bottom of the column, visually disconnected from the dropzone it
belongs to.

- Empty state: the underlag column now sizes to its content and
  top-aligns; the inbox picker renders as a quiet full-width dashed
  row directly under the dropzone ("eller valj befintligt underlag
  fran inkorgen"), so drop-a-file and pick-from-inbox read as one
  intake surface. The fixed-height sticky column returns as soon as
  a document previews there (uploaded, picked, or pre-linked).
- Grid rebalanced from 1fr/520px to 2fr/3fr so the kontering side
  dominates while nothing is being previewed on the left.
- QuickReviewDialog gets the same footer-row treatment for its picker
  trigger inside the underlag collapsible, so both #1620 surfaces
  present the affordance identically (disabled-while-booking kept).

Presentation only: upload path, select-mode picker held until booking,
linkDocuments with inbox_item_id, picked-state resets on close and
transaction change, and duplicate-match wiring are all unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* docs: record the QuickReviewDialog picker-trigger consistency decision

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

DECISIONS.md

@@ -1019,3 +1019,4 @@ One line per decision: `[YYYY-MM-DD] <decision>: <why>`. Appended by agents and
 [2026-08-15] Confirmed intentional (Swedish-review note): with override=true and an unresolvable filename, the attach endpoint links a document to any same-company, same-declared-year, posted verifikat, migrated or not. This mirrors /api/documents/[id]/link, which imposes no filename check at all, so it introduces no new capability class; tenant, year and period-lock enforcement always apply.
 [2026-08-15] BankID tabs bind to a random non-secret `flowId` signed into the shared flow cookie and sent as a request header after start or explicit resume: mode pinning alone cannot distinguish two same-mode tabs, so an older tab could otherwise silently follow, cancel, or complete a newer person's identification after `/start` replaced the origin-wide cookie. This supersedes the 2026-08-15 decision that deliberately skipped mode matching on active polls.
 [2026-08-15] Did not apply BankID migration `20260815120000` to Supabase staging during PR #1625 follow-through: read-only reconciliation found 14 staging-only and 99 branch-only migration versions, so applying on top of that divergent ledger would violate the no-orphan rule. Production is reconciled with zero remote-only versions and exactly this PR migration local-only; hosted pg-real validates the migration until staging is reconciled.
+[2026-08-16] Restyled QuickReviewDialog's inbox-picker trigger to the same full-width dropzone-footer row as TransactionBookingDialog even though it did not share the orphan-button layout: both surfaces come from #1620 and should present the same underlag affordance; the alternative (leaving a small outline button in one dialog and a footer row in the other) would split the visual language of one control. Presentation only, disabled-while-booking kept (PR #1628).