feat: Memento avec dates, Markdown, reminders et auth

Tests Playwright validés ✅:
- Création de notes: OK
- Modification titre: OK
- Modification contenu: OK
- Markdown éditable avec preview: OK

Fonctionnalités:
- date-fns: dates relatives sur cards
- react-markdown + remark-gfm
- Markdown avec toggle edit/preview
- Recherche améliorée (titre/contenu/labels/checkItems)
- Reminder recurrence/location (schema)
- NextAuth.js + User/Account/Session
- userId dans Note (optionnel)
- 4 migrations créées

Ready for production + auth integration

keep-notes/app/actions/notes.ts

@@ -58,8 +58,10 @@ export async function searchNotes(query: string) {
       where: {
         isArchived: false,
         OR: [
-          { title: { contains: query, mode: 'insensitive' } },
-          { content: { contains: query, mode: 'insensitive' } }
+          { title: { contains: query } },
+          { content: { contains: query } },
+          { labels: { contains: query } },
+          { checkItems: { contains: query } }
         ]
       },
       orderBy: [
@@ -68,7 +70,38 @@ export async function searchNotes(query: string) {
       ]
     })
 
-    return notes.map(parseNote)
+    // Enhanced ranking: prioritize title matches
+    const rankedNotes = notes.map(note => {
+      const parsedNote = parseNote(note)
+      let score = 0
+      
+      // Title match gets highest score
+      if (parsedNote.title?.toLowerCase().includes(query.toLowerCase())) {
+        score += 10
+      }
+      
+      // Content match
+      if (parsedNote.content.toLowerCase().includes(query.toLowerCase())) {
+        score += 5
+      }
+      
+      // Label match
+      if (parsedNote.labels?.some(label => label.toLowerCase().includes(query.toLowerCase()))) {
+        score += 3
+      }
+      
+      // CheckItems match
+      if (parsedNote.checkItems?.some(item => item.text.toLowerCase().includes(query.toLowerCase()))) {
+        score += 2
+      }
+      
+      return { note: parsedNote, score }
+    })
+
+    // Sort by score descending, then by existing order (pinned/updated)
+    return rankedNotes
+      .sort((a, b) => b.score - a.score)
+      .map(item => item.note)
   } catch (error) {
     console.error('Error searching notes:', error)
     return []
@@ -85,6 +118,8 @@ export async function createNote(data: {
   labels?: string[]
   images?: string[]
   isArchived?: boolean
+  reminder?: Date | null
+  isMarkdown?: boolean
 }) {
   try {
     const note = await prisma.note.create({
@@ -97,6 +132,8 @@ export async function createNote(data: {
         labels: data.labels ? JSON.stringify(data.labels) : null,
         images: data.images ? JSON.stringify(data.images) : null,
         isArchived: data.isArchived || false,
+        reminder: data.reminder || null,
+        isMarkdown: data.isMarkdown || false,
       }
     })
 
@@ -119,6 +156,8 @@ export async function updateNote(id: string, data: {
   checkItems?: CheckItem[] | null
   labels?: string[] | null
   images?: string[] | null
+  reminder?: Date | null
+  isMarkdown?: boolean
 }) {
   try {
     // Stringify JSON fields if they exist