feat(notes): liens internes, onglet Réseau, living blocks et consentement IA

Rend les liens entre notes visibles et persistants (sync NoteLink au save, auto-save, graphe réseau rafraîchi), ajoute living blocks, Memory Echo, recherche globale, consentement IA explicite et consolide les prototypes design en architectural-grid.

Co-authored-by: Cursor <cursoragent@cursor.com>

memento-note/lib/blocks/extract-blocks.ts

@@ -0,0 +1,73 @@
+export interface ExtractedBlock {
+  blockId: string
+  content: string
+}
+
+export function extractBlocksFromHtml(html: string): ExtractedBlock[] {
+  const blocks: ExtractedBlock[] = []
+  const regex = /<(?:p|h[1-6]|blockquote|li)[^>]*data-id="([^"]+)"[^>]*>([\s\S]*?)<\/(?:p|h[1-6]|blockquote|li)>/gi
+  let match
+  while ((match = regex.exec(html)) !== null) {
+    const blockId = match[1]
+    const content = match[2].replace(/<[^>]+>/g, ' ').replace(/\s+/g, ' ').trim()
+    if (content.length >= 10) {
+      blocks.push({ blockId, content })
+    }
+  }
+  return blocks
+}
+
+export function jaccardSimilarity(a: string, b: string): number {
+  const tokenize = (s: string) =>
+    new Set(
+      s
+        .toLowerCase()
+        .replace(/[^\w\s]/g, '')
+        .split(/\s+/)
+        .filter(w => w.length > 3)
+    )
+  const A = tokenize(a)
+  const B = tokenize(b)
+  if (A.size === 0 || B.size === 0) return 0
+  let intersection = 0
+  A.forEach(w => { if (B.has(w)) intersection++ })
+  return intersection / (A.size + B.size - intersection)
+}
+
+function extractPlainBlocksFromHtml(html: string): ExtractedBlock[] {
+  const blocks: ExtractedBlock[] = []
+  const regex = /<(?:p|h[1-6]|blockquote|li|td|th|div)[^>]*>([\s\S]*?)<\/(?:p|h[1-6]|blockquote|li|td|th|div)>/gi
+  let match
+  while ((match = regex.exec(html)) !== null) {
+    const content = match[1].replace(/<[^>]+>/g, ' ').replace(/\s+/g, ' ').trim()
+    if (content.length >= 10) {
+      blocks.push({ blockId: '', content })
+    }
+  }
+  return blocks
+}
+
+function pickBestFromBlocks(blocks: ExtractedBlock[], hint: string): ExtractedBlock | null {
+  if (blocks.length === 0) return null
+  if (!hint.trim()) return blocks[0]
+
+  let best = blocks[0]
+  let bestScore = jaccardSimilarity(hint, best.content)
+  for (const block of blocks.slice(1)) {
+    const score = jaccardSimilarity(hint, block.content)
+    if (score > bestScore) {
+      best = block
+      bestScore = score
+    }
+  }
+  return best
+}
+
+export function pickBestBlockForHint(html: string, hint: string): ExtractedBlock | null {
+  return pickBestFromBlocks(extractBlocksFromHtml(html), hint)
+}
+
+/** Fallback when notes have no data-id yet (citation statique, pas de bloc vivant). */
+export function pickBestPlainPassageForHint(html: string, hint: string): ExtractedBlock | null {
+  return pickBestFromBlocks(extractPlainBlocksFromHtml(html), hint)
+}