feat(dimensions): PR3 tagging — voucher-form pickers, MCP dimension tools with resolve-don't-select, engine soft validation (#859)

Phase 3 of dev_docs/dimensions_implementation_plan.md. Companies with
dimensions_enabled=false see zero change; existing free-text API writers keep
working (validation is toggle-governed).

Engine (soft validation):
- validateEntryDimensions() in dimension-resolver: zero queries for untagged
  entries; toggle off → passthrough; toggle on → one settings fetch + two
  registry queries, rejects unknown dims/codes and archived values with
  Swedish per-code messages (DimensionValidationError, 400, details.issues).
  Wired into createDraftEntry + updateDraftEntry before any insert; reversal/
  storno paths untouched (verbatim copies). Fails open on transient registry
  errors — soft validation must never block bookkeeping.

MCP (agent write path):
- New tools: gnubok_list_dimensions, gnubok_list_dimension_values (fuse.js
  fuzzy), gnubok_create_dimension_value (STAGED via pending_operations —
  agents never silently mint reporting values; new op type + CHECK migration
  + executor with duplicate-idempotency).
- create_voucher/correct_entry: per-line dimensions bag + default_dimensions,
  resolve-don't-select server-side (code OR natural-language name; exact →
  fuzzy ≤0.30 with ≥0.15 runner-up margin; non-exact resolutions echoed with
  confidence; ambiguous → ranked candidates, no auto-create).
- gnubok_get_agent_briefing gains a dimensions block (enabled, dims, top
  values) — omitted when registry empty.
- TOOL_SCOPE_MAP entries; risk tier low for staged value creation.

UI:
- JournalEntryForm (manual voucher + TransactionBookingDialog embed): header
  "+ Kostnadsställe/Projekt" progressive disclosure (gäller alla rader with
  documented inheritance rule) + per-row tag popover + compact KS·PR badges;
  gated on dimensions_enabled.
- Voucher detail: display-only dimension badges with registry-name resolution.
- EditDraftEntryDialog carries line dimensions so editing a draft no longer
  strips tags.

categorize/bulk_book dims deferred to PR7 (needs the bulk_book RPC migration).

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

lib/errors/structured-errors.ts

@@ -206,6 +206,17 @@ const BOOKKEEPING: Record<string, StructuredErrorEntry> = {
     message_sv: 'Kontering saknas för transaktionen. Kontrollera bokföringsreglerna.',
     message_en: 'Mapping rules produced an invalid debit/credit account pair.',
   },
+  DIMENSION_VALIDATION_FAILED: {
+    httpStatus: 400,
+    message_sv:
+      'Ett angivet kostnadsställe/projekt finns inte i dimensionsregistret eller är arkiverat. Skapa värdet i registret först.',
+    message_en:
+      'One or more dimension codes on the entry lines are missing from the dimension registry or archived. details.issues lists each offending sie_dim_no/code.',
+    remediation: {
+      description:
+        'Create the missing dimension value in the register (or re-activate the archived value), then retry. Only companies with dimensions enabled are validated; each issue in details.issues carries sie_dim_no, code and reason (unknown_dimension | unknown_value | archived_value).',
+    },
+  },
   BOOKKEEPING_DATABASE_ERROR: {
     httpStatus: 500,
     message_sv: 'Verifikationen kunde inte sparas. Försök igen.',