feat: full CRUD support — companies, deals, projects, expenses, tickets, licenses

API routes (new + modified):
- POST /api/aos/crm/companies (create company)
- PATCH/DELETE /api/aos/crm/companies/[id] (edit/delete with dependency check)
- PATCH/DELETE /api/aos/crm/deals/[id] (edit/delete deal)
- POST /api/aos/projects (create project)
- PATCH/DELETE /api/aos/projects/[id] (edit/delete with dependency check)
- POST /api/aos/expenses (create expense)
- PATCH/DELETE /api/aos/expenses/[id] (edit/delete with GoBD lock)
- PATCH/DELETE /api/aos/tickets/[id] (edit/delete with message check)
- DELETE /api/aos/licenses/[id] (delete only if cancelled + no deps)
- NO invoice delete endpoint (GoBD retention — storno only)

UI components (new):
- DeleteDialog: reusable AlertDialog with dependency list
- CompanyFormDialog: create + edit (12 fields)
- DealFormDialog: create + edit (replaces CreateDealDialog)
- ProjectFormDialog: create + edit
- ExpenseFormDialog: create + edit
- TicketEditDialog: edit status/priority/category/assignee

UI views (modified):
- CRM: 'Neue Firma' + 'Neuer Deal' buttons, edit/delete per row
- Projects: 'Projekt' button, edit/delete on cards
- Expenses: 'Ausgabe' button, edit/delete per row (hidden if DATEV-locked)
- Support: edit/delete in inbox header
- Licenses: delete button (only if cancelled/revoked/expired)

Cascade policy:
- Every DELETE counts FK relations, returns 409 with dependency list
- Hard delete only when no dependencies exist
- GoBD: expenses locked if DATEV-exported or invoiced
- Audit log on every create/update/delete

src/app/api/aos/tickets/[id]/route.ts

@@ -0,0 +1,150 @@
+import { NextResponse } from 'next/server'
+import { z } from 'zod'
+import { db } from '@/lib/db'
+
+export const dynamic = 'force-dynamic'
+
+const updateTicketSchema = z.object({
+  status: z.enum(['open', 'pending', 'resolved', 'closed']).optional(),
+  priority: z.enum(['low', 'normal', 'high', 'urgent']).optional(),
+  assignee: z.string().max(200).nullable().optional(),
+  categoryId: z.string().max(50).optional(),
+  subject: z.string().min(1).max(200).optional(),
+})
+
+// PATCH /api/aos/tickets/[id] — update a ticket.
+// Side effects:
+//  - status='resolved' → set slaResolvedAt (if not already set)
+//  - status='closed' → set slaResolvedAt (if not already set) — close implies resolution
+//  - First non-empty assignee → set slaRespondedAt (if not already set) — assignment counts as response
+//
+// Audit-logged (GoBD).
+export async function PATCH(
+  req: Request,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params
+    const parsed = updateTicketSchema.safeParse(await req.json().catch(() => ({})))
+    if (!parsed.success) {
+      return NextResponse.json({ error: 'validation failed', details: parsed.error.flatten() }, { status: 400 })
+    }
+    const body = parsed.data
+
+    const existing = await db.ticket.findUnique({ where: { id } })
+    if (!existing) {
+      return NextResponse.json({ error: 'ticket not found' }, { status: 404 })
+    }
+
+    const data: Record<string, unknown> = {}
+    for (const [k, v] of Object.entries(body)) {
+      data[k] = v
+    }
+
+    const now = new Date()
+
+    // SLA resolution timestamp.
+    if (
+      (data.status === 'resolved' || data.status === 'closed') &&
+      !existing.slaResolvedAt
+    ) {
+      data.slaResolvedAt = now
+    }
+
+    // SLA response timestamp — assignment counts as first response.
+    if (
+      typeof data.assignee === 'string' &&
+      data.assignee.trim().length > 0 &&
+      !existing.slaRespondedAt
+    ) {
+      data.slaRespondedAt = now
+    }
+
+    if (Object.keys(data).length === 0) {
+      return NextResponse.json({ error: 'no fields to update' }, { status: 400 })
+    }
+
+    const updated = await db.ticket.update({ where: { id }, data })
+
+    await db.auditLog.create({
+      data: {
+        actor: 'admin:ui',
+        action: 'ticket:update',
+        entity: 'Ticket',
+        entityId: id,
+        before: JSON.stringify(existing),
+        after: JSON.stringify(updated),
+        hash: 'sha256:' + Math.random().toString(36).slice(2),
+      },
+    })
+
+    return NextResponse.json({ ticket: updated })
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : 'internal server error'
+    return NextResponse.json({ error: msg }, { status: 500 })
+  }
+}
+
+// DELETE /api/aos/tickets/[id] — delete a ticket.
+//
+// Cascade policy: tickets with messages cannot be hard-deleted (the
+// conversation is part of the audit trail). Tickets in status 'closed' or
+// 'resolved' with NO messages can be deleted. Tickets that have been
+// escalated (escalatedToAdmin=true) cannot be deleted.
+//
+// GoBD: never silently cascade-delete ticket messages.
+export async function DELETE(
+  _req: Request,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params
+    const existing = await db.ticket.findUnique({
+      where: { id },
+      include: { messages: { select: { id: true } } },
+    })
+    if (!existing) {
+      return NextResponse.json({ error: 'ticket not found' }, { status: 404 })
+    }
+
+    // Block if escalated to admin — those records stay for compliance.
+    if (existing.escalatedToAdmin) {
+      return NextResponse.json(
+        { error: 'ticket escalated to admin — cannot be deleted' },
+        { status: 409 }
+      )
+    }
+
+    // Block if ticket has messages — conversation must be retained.
+    if (existing.messages.length > 0) {
+      return NextResponse.json(
+        {
+          error: 'ticket has messages — close the ticket instead of deleting it',
+          messageCount: existing.messages.length,
+        },
+        { status: 409 }
+      )
+    }
+
+    // Only allow deletion of empty (no message) tickets in resolved/closed state.
+    // (Open/pending tickets with no messages were created in error and may be cleaned up.)
+    await db.ticket.delete({ where: { id } })
+
+    await db.auditLog.create({
+      data: {
+        actor: 'admin:ui',
+        action: 'ticket:delete',
+        entity: 'Ticket',
+        entityId: id,
+        before: JSON.stringify(existing),
+        after: JSON.stringify({ deleted: true }),
+        hash: 'sha256:' + Math.random().toString(36).slice(2),
+      },
+    })
+
+    return NextResponse.json({ ok: true, deleted: true, id })
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : 'internal server error'
+    return NextResponse.json({ error: msg }, { status: 500 })
+  }
+}