fix(health): add /api/v1/health endpoint for healthchecks

Health endpoint required for Docker Compose and Kubernetes healthchecks.
Returns simple JSON with status, timestamp, and service name.

Placed before other routes to minimize middleware overhead.
No authentication required as this is a public health status endpoint.

Fixes: P1.6 from audit AUDIT_TEMP_29_01_2026.md

veza-backend-api/internal/api/router.go

@@ -262,6 +262,16 @@ func (r *APIRouter) Setup(router *gin.Engine) error {
 	// BE-SVC-019: Apply version middleware to API routes
 	router.Use(VersionMiddleware(r.versionManager))
 
+	// P1.6: Health endpoint for Docker/K8s healthchecks
+	// Must be before other routes to avoid middleware overhead
+	router.GET("/api/v1/health", func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{
+			"status":    "ok",
+			"timestamp": time.Now().Unix(),
+			"service":   "veza-backend-api",
+		})
+	})
+
 	// Routes core publiques (health, metrics, upload info)
 	r.setupCorePublicRoutes(router)