Add backend/frontend scaffolding with Oracle ADB wallet config

- Backend: Spring Boot 3 + WebFlux, JWT auth, Oracle ADB wallet,
  8 controllers/services/repositories (Auth~Tag), DTOs, exception handling
- Frontend: Next.js 15, TypeScript, Tailwind CSS, AuthContext,
  7 pages (dashboard, knowledge, chat, study, todos, habits, login)
- DB: V1 migration with 12 tables including VECTOR(1024) + HNSW index
- Ops: PM2 ecosystem config, deploy.sh, start-backend.sh
- CLAUDE.md: DB credentials replaced with env var references

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ecosystem.config.cjs

@@ -0,0 +1,23 @@
+module.exports = {
+  apps: [
+    {
+      name: "sundol-backend",
+      script: "./start-backend.sh",
+      interpreter: "/bin/bash",
+      cwd: "/home/opc/sundol",
+      env: {
+        JAVA_HOME: "/usr/lib/jvm/java-21",
+      },
+    },
+    {
+      name: "sundol-frontend",
+      script: "node",
+      args: "sundol-frontend/.next/standalone/server.js",
+      cwd: "/home/opc/sundol",
+      env: {
+        PORT: 3000,
+        HOSTNAME: "0.0.0.0",
+      },
+    },
+  ],
+};