feat: auto-fill mockup dimensions and family from Google Sheets

- Extend Sheets read range from A1:Z to A1:AZ (52 columns)
- Parse longueur, largeur, marque, famille, sousFamille, prixRemise, specificFields
- Add /api/products/sheet-info endpoint to fetch product data by ref
- Auto-fill family and dimensions on product selection in all 3 mockup entry points
- Strengthen carrelage mockup prompt with strict tile-size consistency rules

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/(dashboard)/mockup/page.tsx

@@ -10,6 +10,9 @@ interface Product {
   shopifyId: string
   title: string
   ref: string
+  famille?: string
+  longueur?: string
+  largeur?: string
 }
 
 export default function MockupPage() {
@@ -91,7 +94,20 @@ export default function MockupPage() {
                       <div className="absolute z-10 mt-1 w-full bg-slate-700 border border-slate-600 rounded shadow-lg max-h-56 overflow-y-auto">
                         {filtered.map(p => (
                           <button key={p.shopifyId} type="button"
-                            onMouseDown={() => { setSelectedProduct(p); setSearch(''); setShowDropdown(false) }}
+                            onMouseDown={() => {
+                              setSelectedProduct(p)
+                              setSearch('')
+                              setShowDropdown(false)
+                              fetch(`/api/products/sheet-info?ref=${encodeURIComponent(p.ref)}`)
+                                .then(r => r.ok ? r.json() : null)
+                                .then(data => {
+                                  if (!data?.product) return
+                                  const { famille, longueur, largeur } = data.product
+                                  if (famille) setFamily(famille)
+                                  if (longueur && largeur) setDimensions(`${longueur}x${largeur}cm`)
+                                  else if (longueur) setDimensions(`${longueur}cm`)
+                                })
+                            }}
                             className="w-full text-left px-3 py-2 text-sm text-white hover:bg-slate-600 flex justify-between gap-2">
                             <span className="truncate">{p.title}</span>
                             <span className="text-xs text-gray-400 shrink-0">{p.ref}</span>

src/app/api/mockup/generate/route.ts

@@ -6,17 +6,33 @@ import { getTemplateImagePath, listTemplates } from '@/lib/mockupTemplates'
 import type { MockupGenerateRequest } from '@/types/mockup'
 
 function buildPrompt(req: MockupGenerateRequest): string {
-  let carrelageContext = 'tiles covering the floor or wall of a modern room'
-  if (req.family === 'Carrelage' && req.placement === 'mur') {
-    carrelageContext = 'wall tiles (faïence) covering the wall of a modern bathroom or kitchen — applied only to the wall, not the floor'
-  } else if (req.family === 'Carrelage' && req.placement === 'sol') {
-    carrelageContext = 'floor tiles covering the floor of a modern room — applied only to the floor, not the walls'
+  if (req.family === 'Carrelage') {
+    let surface = 'floor or wall'
+    let restriction = ''
+    if (req.placement === 'mur') {
+      surface = 'wall'
+      restriction = ' Apply tiles only to the wall surface, not the floor.'
+    } else if (req.placement === 'sol') {
+      surface = 'floor'
+      restriction = ' Apply tiles only to the floor surface, not the walls.'
+    }
+    const dimClause = req.dimensions
+      ? ` The real-world tile size is ${req.dimensions}.`
+      : ''
+    const instructionClause = req.instruction ? ` Additional instruction: ${req.instruction}.` : ''
+
+    return `Replace the ${surface} covering in the reference scene with the provided tile image (${req.productName}).${dimClause}${restriction} CRITICAL RULES — you MUST follow all of them:
+1. Every single tile in the entire image must be EXACTLY the same size — no exceptions anywhere in the scene.
+2. The tile pattern must be a perfectly uniform grid: identical tile dimensions repeated consistently across the entire ${surface}.
+3. Tiles may be partially cut at edges, corners, or where the ${surface} meets other surfaces — but each visible portion must match the same grid unit size.
+4. NEVER vary the tile scale or apparent size in different parts of the image, even for artistic or perspective reasons.
+5. Copy the tile design, texture, color, and proportions from the provided image exactly — do not alter them.
+6. Maintain realistic lighting and perspective consistent with the reference scene.${instructionClause}`
   }
 
   const familyContext: Record<string, string> = {
     'Menuiserie': 'door installed in a residential entrance or hallway, visible wall and floor context',
     'Baies vitrées': 'bay window or sliding door installed in a living room with garden view',
-    'Carrelage': carrelageContext,
   }
   const context = familyContext[req.family] ?? 'product installed in an appropriate room setting'
   const dimClause = req.dimensions

src/app/api/products/sheet-info/route.ts

@@ -0,0 +1,19 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { getServerSession } from 'next-auth'
+import { authOptions } from '@/lib/auth'
+import { readSheetProducts } from '@/lib/googleSheets'
+
+export async function GET(req: NextRequest) {
+  const session = await getServerSession(authOptions)
+  if (!session) return NextResponse.json({ error: 'Non authentifié' }, { status: 401 })
+
+  const ref = new URL(req.url).searchParams.get('ref')
+  if (!ref) return NextResponse.json({ error: 'Paramètre ref manquant' }, { status: 400 })
+
+  const products = await readSheetProducts()
+  const product = products.find(p => p.ref.toLowerCase() === ref.toLowerCase())
+
+  if (!product) return NextResponse.json({ error: 'Produit non trouvé' }, { status: 404 })
+
+  return NextResponse.json({ product })
+}