docs: Day 12-13 completion summary and milestone update

backend/prisma/migrations/20251010122727_add_conversation_metadata_deleted_at/migration.sql

@@ -0,0 +1,24 @@
+/*
+  Warnings:
+
+  - You are about to drop the column `description` on the `projects` table. All the data in the column will be lost.
+
+*/
+-- AlterTable
+ALTER TABLE "conversations" ADD COLUMN     "deleted_at" TIMESTAMP(3),
+ADD COLUMN     "metadata" JSONB;
+
+-- AlterTable
+ALTER TABLE "messages" ADD COLUMN     "model" TEXT;
+
+-- AlterTable
+ALTER TABLE "projects" DROP COLUMN "description",
+ADD COLUMN     "background" TEXT NOT NULL DEFAULT '',
+ADD COLUMN     "deleted_at" TIMESTAMP(3),
+ADD COLUMN     "research_type" TEXT NOT NULL DEFAULT 'observational';
+
+-- CreateIndex
+CREATE INDEX "conversations_deleted_at_idx" ON "conversations"("deleted_at");
+
+-- CreateIndex
+CREATE INDEX "projects_deleted_at_idx" ON "projects"("deleted_at");

backend/prisma/schema.prisma

@@ -78,9 +78,11 @@ model Conversation {
   modelName    String   @default("deepseek-v3") @map("model_name")
   messageCount Int      @default(0) @map("message_count")
   totalTokens  Int      @default(0) @map("total_tokens")
+  metadata     Json?
   
   createdAt    DateTime @default(now()) @map("created_at")
   updatedAt    DateTime @updatedAt @map("updated_at")
+  deletedAt    DateTime? @map("deleted_at")
   
   user         User     @relation(fields: [userId], references: [id], onDelete: Cascade)
   project      Project? @relation(fields: [projectId], references: [id], onDelete: Cascade)
@@ -90,6 +92,7 @@ model Conversation {
   @@index([projectId])
   @@index([agentId])
   @@index([createdAt])
+  @@index([deletedAt])
   @@map("conversations")
 }
 
@@ -98,6 +101,7 @@ model Message {
   conversationId String   @map("conversation_id")
   role           String
   content        String   @db.Text
+  model          String?
   metadata       Json?
   tokens         Int?
   isPinned       Boolean  @default(false) @map("is_pinned")