feat: migrate semantic search to pgvector + full-text search

Replace JSON-string embeddings with native pgvector(1536) storage and
add PostgreSQL full-text search (tsvector/GIN) with Reciprocal Rank Fusion
for hybrid keyword + semantic ranking.

Changes:
- NoteEmbedding.embedding: String → vector(1536) via pgvector
- NoteEmbedding: added updatedAt for reindex tracking
- Note: added tsv (tsvector) with auto-update trigger for FTS
- semantic-search.service: hybrid FTS + vector search with RRF fusion
- embedding.service: toVectorString() for pgvector SQL literals
- Removed JS-side cosine similarity loops (now DB-side via <=>)
- Added HNSW index on NoteEmbedding.embedding (cosine distance)
- Added GIN index on Note.tsv for FTS queries

Schema migration in: prisma/migrations/20260512120000_pgvector_and_fts_search/

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

architectural-grid10/src/components/SettingsView.tsx

@@ -0,0 +1,66 @@
+import React from 'react';
+import { motion, AnimatePresence } from 'motion/react';
+import { SettingsTab } from '../types';
+import { SettingsHeader } from './settings/SettingsHeader';
+import { GeneralTab } from './settings/GeneralTab';
+import { AITab } from './settings/AITab';
+import { AppearanceTab } from './settings/AppearanceTab';
+
+interface SettingsViewProps {
+  activeSettingsTab: SettingsTab;
+  setActiveSettingsTab: (tab: SettingsTab) => void;
+}
+
+export const SettingsView: React.FC<SettingsViewProps> = ({
+  activeSettingsTab,
+  setActiveSettingsTab
+}) => {
+  return (
+    <div className="h-full flex flex-col bg-paper dark:bg-dark-paper overflow-y-auto custom-scrollbar relative font-sans">
+      <div className="absolute inset-0 opacity-[0.04] pointer-events-none grainy-bg mix-blend-multiply dark:mix-blend-overlay" />
+      
+      <div className="relative z-10 flex flex-col min-h-full">
+        <SettingsHeader 
+          activeTab={activeSettingsTab} 
+          setActiveTab={setActiveSettingsTab} 
+        />
+
+        <div className="flex-1 px-12 pb-24 h-full">
+          <div className="max-w-6xl mx-auto">
+            <AnimatePresence mode="wait">
+              {activeSettingsTab === 'general' && (
+                <GeneralTab key="general" />
+              )}
+
+              {activeSettingsTab === 'ai' && (
+                <AITab key="ai" />
+              )}
+
+              {activeSettingsTab === 'appearance' && (
+                <AppearanceTab key="appearance" />
+              )}
+
+              {['profile', 'data', 'mcp', 'about'].includes(activeSettingsTab) && (
+                <motion.div 
+                  key="placeholder"
+                  initial={{ opacity: 0, y: 10 }}
+                  animate={{ opacity: 1, y: 0 }}
+                  exit={{ opacity: 0, y: -10 }}
+                  className="h-[50vh] flex flex-col items-center justify-center border border-dashed border-border rounded-[32px] space-y-6 bg-white/20 dark:bg-white/5"
+                >
+                  <div className="w-16 h-16 rounded-3xl border border-dashed border-concrete/20 flex items-center justify-center text-concrete/40 bg-paper/50">
+                    <span className="text-2xl font-serif italic text-concrete">?</span>
+                  </div>
+                  <div className="text-center space-y-1">
+                    <p className="text-ink font-bold text-sm tracking-tight">Section en développement</p>
+                    <p className="text-concrete italic text-[11px] font-light">Le module {activeSettingsTab} sera disponible prochainement.</p>
+                  </div>
+                </motion.div>
+              )}
+            </AnimatePresence>
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+};