refactor(structure): promote app to repo root + remove redundant workspace cruft

Standard production layout: the OKR app (was nested under AINative_OKR_CASAN5/) is now
the repository root. No more wrapper directory.

- Promote AINative_OKR_CASAN5/* -> repo root (backend/ frontend/ packages/ apps/
  .specify/ docs/ infra/ nginx/ scripts/ + configs). Merge tool dirs: .gitea (kept the
  active deploy ci.yml, added harness-ci.yml + runbooks), .claude (agents/commands +
  launch.json), .github moved up.
- Remove redundant: 00_SUBMISSION_PACKAGE, scattered root notes (FPT_CASAN_Full.md,
  tu-tuong-casan.md, casan-tu-sinh..., casan_harness_assessment.md, source-review...,
  README_CASAN5_REFINED.md), casan-next-plans/ and optimize-docs/ (competition/planning
  artifacts — roadmap + design history preserved in git log / commit messages).
- Update all references to the old layout:
  - .gitea/workflows/{ci,harness-ci}.yml, .github/workflows/{ci,deploy}.yml:
    working-directory .; drop AINative_OKR_CASAN5/ prefix; .specify/{tests,scripts}
    -> packages/casan-harness/... (.specify/logs state kept)
  - .claude/launch.json, .gitea/*-runbook.md: path prefixes
  - CLAUDE.md, README.md: docs/input -> apps/okr/domain/input
  - policy-bundle.yaml: 8 policy paths -> packages/casan-harness/...; manifest re-signed
- secrets-scan.sh: fixture excludes -> new package/domain paths.

Full gate from the new root: PASS=64 FAIL=0 SKIP=3.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/prisma/schema.prisma

@@ -0,0 +1,63 @@
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "mysql"
+  url      = env("DATABASE_URL")
+}
+
+model User {
+  id           Int         @id @default(autoincrement())
+  name         String
+  username     String      @unique
+  email        String      @unique
+  passwordHash String
+  role         String
+  objectives   Objective[]
+  createdAt    DateTime    @default(now())
+  updatedAt    DateTime    @updatedAt
+}
+
+model Objective {
+  id          Int             @id @default(autoincrement())
+  title       String
+  description String?
+  ownerId     Int
+  owner       User            @relation(fields: [ownerId], references: [id])
+  quarter     String
+  status      String   @default("NOT_STARTED")
+  keyResults  KeyResult[]
+  createdAt   DateTime        @default(now())
+  updatedAt   DateTime        @updatedAt
+
+  @@index([ownerId])
+  @@index([quarter])
+  @@index([status])
+}
+
+model KeyResult {
+  id          Int        @id @default(autoincrement())
+  objectiveId Int
+  objective   Objective  @relation(fields: [objectiveId], references: [id], onDelete: Cascade)
+  title       String
+  progress    Int        @default(0)
+  startValue  Int
+  targetValue Int
+  deadline    DateTime
+  updates     ProgressUpdate[]
+  createdAt   DateTime   @default(now())
+  updatedAt   DateTime   @updatedAt
+
+  @@index([objectiveId])
+}
+
+model ProgressUpdate {
+  id          Int       @id @default(autoincrement())
+  keyResultId Int
+  keyResult   KeyResult @relation(fields: [keyResultId], references: [id], onDelete: Cascade)
+  progress    Int
+  comment     String?
+  createdById Int
+  createdAt   DateTime  @default(now())
+}