[Core]: Import/Export Options for all data

[nielsdrost7]

Epic — Import / Export options across all data modules

This issue tracks the full import/export surface for InvoicePlane v2. Child issues implement the individual module-level actions.

v2 approach: All imports use Filament's built-in ImportAction with a per-module Importer class. All exports use Filament's ExportAction with a per-module Exporter class. No custom HTTP routes are needed.

---

Child issues

Module	Import	Export
Products	#140 (CSV/Excel import)	—
Clients	#141 (CSV import)	—
Catalogs/Pricelists	#139 (CSV/Excel import)	—
Excel support	#80 (.xlsx file handling)	—
Invoices	—	TBD
Quotes	—	TBD
Payments	—	TBD
Expenses	—	TBD
Full backup	—	TBD

---

Acceptance criteria (Epic-level)

• Each data module has an Import button (where applicable) on its list page.
• Each data module has an Export CSV button on its list page.
• Import: invalid rows are skipped with per-row error reports.
• Import: uses firstOrCreate / updateOrCreate to avoid duplicates.
• Import: all imports are company-scoped.
• Export: CSV downloads include a header row and data rows for the current company.
• A "full backup" export (all modules, one ZIP) is out of scope for v2.0 alpha.

---

Technical standards

• Importer classes: Modules/<Module>/Filament/Company/Imports/<Model>Importer.php
• Exporter classes: Modules/<Module>/Filament/Company/Exports/<Model>Exporter.php
• Each must ship PHPUnit feature tests covering: successful import, skipped invalid row, company scoping.
• No raw $response->get(route(...)) in tests — use Livewire ->callAction('import', ...) and ->callAction('export', ...) patterns.