feat: 이미지 업로드용 GCS Signed URL 발급 API

.env.template

@@ -7,3 +7,6 @@ SERVER_PORT=8080
 CORS_ALLOWED_ORIGINS=http://localhost:3000
 SWAGGER_USER=ppotto
 SWAGGER_PASSWORD=ppotto
+GCS_BUCKET=
+GCS_CREDENTIALS_PATH=./secrets/gcs-service-account.json
+GCS_SIGNED_URL_EXPIRATION_MINUTES=60

.gitignore

@@ -10,3 +10,4 @@ out/
 .env
 .env.*
 !.env.template
+/secrets/

AGENTS.md

@@ -55,7 +55,7 @@ photo/
 ## Planned Conventions
 
 - Primary keys for new tables: `uuid primary key default uuidv7()` (Postgres 18 built-in, time-ordered).
-- API versioning: adopt Spring Framework 7 native API versioning when the first public API ships.
+- API versioning: 첫 공개 API(`analysis/presentation/AnalysisController.kt`)는 `/api/v1/...` URL 경로 프리픽스로 버저닝했다 — Spring Framework 7 네이티브 API 버저닝(`ApiVersionConfigurer`)은 아직 도입하지 않음. 다음 공개 API를 추가할 때 네이티브 버저닝으로 전환할지, 경로 프리픽스 방식을 계속 쓸지 결정 필요.
 
 ## DB Workflow
 

build.gradle.kts

@@ -35,6 +35,7 @@ dependencies {
     implementation(platform(libs.spring.cloud.dependencies))
 
     implementation(libs.flyway.database.postgresql)
+    implementation(libs.google.cloud.storage)
     implementation(libs.jackson.module.kotlin)
     implementation(libs.jooq.kotlin)
     implementation(libs.kotlin.reflect)

gradle/libs.versions.toml

@@ -5,6 +5,7 @@ spring-dependency-management = "1.1.7"
 spring-cloud = "2025.1.2"
 jooq = "3.21.6"
 flyway = "12.4.0"
+google-cloud-storage = "2.70.0"
 postgresql = "42.7.11"
 kotest = "6.2.3"
 spring-dotenv = "5.1.0"
@@ -31,6 +32,7 @@ kotlin-reflect = { module = "org.jetbrains.kotlin:kotlin-reflect" }
 jackson-module-kotlin = { module = "tools.jackson.module:jackson-module-kotlin" }
 jooq-kotlin = { module = "org.jooq:jooq-kotlin", version.ref = "jooq" }
 flyway-database-postgresql = { module = "org.flywaydb:flyway-database-postgresql", version.ref = "flyway" }
+google-cloud-storage = { module = "com.google.cloud:google-cloud-storage", version.ref = "google-cloud-storage" }
 postgresql = { module = "org.postgresql:postgresql", version.ref = "postgresql" }
 spring-dotenv = { module = "me.paulschwarz:springboot4-dotenv", version.ref = "spring-dotenv" }
 testcontainers-junit-jupiter = { module = "org.testcontainers:testcontainers-junit-jupiter" }