refactor(agent): keep the assistant in the nav, FAB and underlag flow only (#1557)

The founder wants the scattered per-page assistant buttons gone: the
assistant is reachable from the nav and the floating tab everywhere, so
in-page duplicates were noise. Removed the AgentSparkleButton call sites
(year-end, verifikat detail, supplier invoice detail, invoice editor)
and the now-orphaned component, the soft hand-off link in the Ny
verifikat modal (plus its i18n keys), and the transaction-row overflow
item. Kept: nav entry, floating tab, the Dokumentinkorg flow, and the
sanctioned "Skapa med assistent" split-button mode on /bookkeeping
(design.md convention 14).

The command palette's hand-off entries hardcoded the agent name "Anna";
they now use the identity from AgentSheetProvider like every other
affordance, and hide until agent onboarding is done (same gate as the
FAB).

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

components/invoices/InvoiceEditor.tsx

@@ -56,7 +56,6 @@ import { FirstInvoiceLogoPrompt } from '@/components/invoices/FirstInvoiceLogoPr
 import { useCompany, useCapability } from '@/contexts/CompanyContext'
 import { CAPABILITY } from '@/lib/entitlements/keys'
 import { ENABLED_EXTENSION_IDS } from '@/lib/extensions/_generated/enabled-extensions'
-import AgentSparkleButton from '@/components/agent/AgentSparkleButton'
 import {
   ROT_WORK_TYPES,
   RUT_WORK_TYPES,
@@ -1470,11 +1469,6 @@ export default function InvoiceEditor(props: InvoiceEditorProps = { mode: 'creat
           </Heading>
           {!bare && <p className="text-muted-foreground">{subtitleText}</p>}
         </div>
-        <AgentSparkleButton
-          intentId="invoice.draft"
-          intentArgs={{ customer_id: watchCustomerId ?? null }}
-          contextRef={watchCustomerId ? `customer:${watchCustomerId}` : 'invoice:new'}
-        />
       </div>
 
       {isCopyMode && copyInitial && (