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>

sundol-backend/src/main/resources/application.yml

@@ -0,0 +1,24 @@
+server:
+  port: ${SERVER_PORT:8080}
+
+oracle:
+  wallet-path: ${ORACLE_WALLET_PATH}
+  tns-name: ${ORACLE_TNS_NAME}
+  username: ${ORACLE_USERNAME}
+  password: ${ORACLE_PASSWORD}
+
+jwt:
+  secret: ${JWT_SECRET}
+  access-token-expiry: ${JWT_ACCESS_TOKEN_EXPIRY:900000}
+  refresh-token-expiry: ${JWT_REFRESH_TOKEN_EXPIRY:604800000}
+
+cors:
+  origin: ${CORS_ORIGIN:http://localhost:3000}
+
+oci:
+  compartment-id: ${OCI_COMPARTMENT_ID:}
+  region: ${OCI_REGION:ap-seoul-1}
+
+logging:
+  level:
+    com.sundol: DEBUG